From 2a48ce9185f619e21641854ea0538cdfa3d70b42 Mon Sep 17 00:00:00 2001
From: Andrew Werner <awerner32@gmail.com>
Date: Mon, 18 Jul 2022 18:44:27 -0400
Subject: [PATCH 1/6] sql/row: pretty print CPut expectation for kv trace

Release note: None
---
 .../execbuilder/testdata/secondary_index_column_families    | 6 +++---
 pkg/sql/row/updater.go                                      | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/pkg/sql/opt/exec/execbuilder/testdata/secondary_index_column_families b/pkg/sql/opt/exec/execbuilder/testdata/secondary_index_column_families
index 3934b9f69e16..0076ccda9c31 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/secondary_index_column_families
+++ b/pkg/sql/opt/exec/execbuilder/testdata/secondary_index_column_families
@@ -227,7 +227,7 @@ Scan /Table/107/2/{NULL-!NULL}
 query T kvtrace(CPut,prefix=/Table/107/2/)
 UPDATE t SET y = 5 WHERE x = 1
 ----
-CPut /Table/107/2/1/1/1 -> /TUPLE/2:2:Int/5 (replacing [10 35 4], if exists)
+CPut /Table/107/2/1/1/1 -> /TUPLE/2:2:Int/5 (replacing /TUPLE/2:2:Int/2, if exists)
 
 # Test composite datatypes.
 statement ok
@@ -400,7 +400,7 @@ InitPut /Table/112/3/2/5/1 -> /TUPLE/8:8:Int/8
 query T kvtrace(Put,Del,CPut,prefix=/Table/112/2/)
 UPDATE t SET b = 4, c = NULL, d = NULL, e = 7, f = NULL WHERE y = 2
 ----
-CPut /Table/112/2/2/1/2/1 -> /TUPLE/3:3:Int/3/1:4:Int/4 (replacing [10 51 6], if exists)
+CPut /Table/112/2/2/1/2/1 -> /TUPLE/3:3:Int/3/1:4:Int/4 (replacing /TUPLE/3:3:Int/3, if exists)
 Del /Table/112/2/2/1/3/1
 CPut /Table/112/2/2/1/4/1 -> /TUPLE/7:7:Int/7 (expecting does not exist)
 Del /Table/112/2/2/1/5/1
@@ -491,4 +491,4 @@ CPut /Table/113/2/5/1/0 -> /BYTES/0x33061308 (expecting does not exist)
 query T kvtrace(Put,Del,CPut,prefix=/Table/113/2/)
 UPDATE t SET z = 5 where y = 5
 ----
-CPut /Table/113/2/5/1/0 -> /BYTES/0x330a1308 (replacing [3 51 6 19 8], if exists)
+CPut /Table/113/2/5/1/0 -> /BYTES/0x330a1308 (replacing /BYTES/0x33061308, if exists)
diff --git a/pkg/sql/row/updater.go b/pkg/sql/row/updater.go
index f0eefa66721d..aa9e3b50e962 100644
--- a/pkg/sql/row/updater.go
+++ b/pkg/sql/row/updater.go
@@ -426,7 +426,7 @@ func (ru *Updater) UpdateRow(
 							k := keys.PrettyPrint(ru.Helper.secIndexValDirs[i], newEntry.Key)
 							v := newEntry.Value.PrettyPrint()
 							if expValue != nil {
-								log.VEventf(ctx, 2, "CPut %s -> %v (replacing %v, if exists)", k, v, expValue)
+								log.VEventf(ctx, 2, "CPut %s -> %v (replacing %v, if exists)", k, v, oldEntry.Value.PrettyPrint())
 							} else {
 								log.VEventf(ctx, 2, "CPut %s -> %v (expecting does not exist)", k, v)
 							}

From a3da7b0659ed6290ae45a8f7d58b5f156e10bc83 Mon Sep 17 00:00:00 2001
From: Andrew Werner <awerner32@gmail.com>
Date: Mon, 18 Jul 2022 18:54:38 -0400
Subject: [PATCH 2/6] sql/schemachanger: properly transition indexes to
 WRITE_ONLY, add rules

Release note: None
---
 .../schemafeed/testdata/add_column            |   9 +-
 .../testdata/boundedstaleness/single_row      |  12 +-
 .../testdata/end_to_end/create_index          |  65 +++++++----
 .../testdata/explain/create_index             |  23 ++--
 .../testdata/explain_verbose/create_index     |  44 +++++--
 .../scexec/scmutationexec/column.go           |  13 +++
 .../scexec/scmutationexec/index.go            |  44 ++++++-
 pkg/sql/schemachanger/scop/mutation.go        |  16 +++
 .../scop/mutation_visitor_generated.go        |  12 ++
 .../internal/opgen/opgen_primary_index.go     |  19 +++-
 .../internal/opgen/opgen_secondary_index.go   |  19 +++-
 .../internal/rules/dep_index_and_column.go    |  81 ++++++++++---
 .../scplan/internal/rules/testdata/deprules   |  47 ++++++--
 .../scplan/internal/rules/testdata/oprules    |  12 +-
 .../schemachanger/scplan/testdata/alter_table |  93 ++++++++++-----
 .../scplan/testdata/create_index              |  58 +++++++---
 .../schemachanger/scplan/testdata/drop_index  |   8 ++
 .../end_to_end/alter_table_add_column         |  75 ++++++++----
 .../alter_table_add_column_default_seq        | 107 ++++++++++++------
 .../testdata/end_to_end/create_index          |  65 +++++++----
 .../testdata/explain/alter_table_add_column   |  23 ++--
 .../alter_table_add_column_default_seq        |  24 ++--
 .../testdata/explain/create_index             |  23 ++--
 .../explain_verbose/alter_table_add_column    |  49 +++++---
 .../alter_table_add_column_default_seq        |  52 ++++++---
 .../testdata/explain_verbose/create_index     |  44 +++++--
 .../drop_index_hash_sharded_index             |   9 +-
 .../drop_index_partial_expression_index       |   9 +-
 28 files changed, 775 insertions(+), 280 deletions(-)

diff --git a/pkg/ccl/changefeedccl/schemafeed/testdata/add_column b/pkg/ccl/changefeedccl/schemafeed/testdata/add_column
index d8e2973bdbb8..dd4ad0614123 100644
--- a/pkg/ccl/changefeedccl/schemafeed/testdata/add_column
+++ b/pkg/ccl/changefeedccl/schemafeed/testdata/add_column
@@ -26,9 +26,10 @@ t 4->5: Unknown
 t 5->6: Unknown
 t 6->7: Unknown
 t 7->8: Unknown
-t 8->9: AddColumnWithBackfill|PrimaryKeyChange
-t 9->10: Unknown
+t 8->9: Unknown
+t 9->10: AddColumnWithBackfill|PrimaryKeyChange
 t 10->11: Unknown
+t 11->12: Unknown
 
 exec
 SET use_declarative_schema_changer=off;
@@ -37,6 +38,6 @@ ALTER TABLE t ADD COLUMN l INT NOT NULL DEFAULT 42;
 
 pop f=1
 ----
-t 11->12: Unknown
 t 12->13: Unknown
-t 13->14: AddColumnWithBackfill
+t 13->14: Unknown
+t 14->15: AddColumnWithBackfill
diff --git a/pkg/ccl/kvccl/kvfollowerreadsccl/testdata/boundedstaleness/single_row b/pkg/ccl/kvccl/kvfollowerreadsccl/testdata/boundedstaleness/single_row
index 8eacb82e694b..38ff52cd806d 100644
--- a/pkg/ccl/kvccl/kvfollowerreadsccl/testdata/boundedstaleness/single_row
+++ b/pkg/ccl/kvccl/kvfollowerreadsccl/testdata/boundedstaleness/single_row
@@ -185,7 +185,7 @@ query idx=2 wait-until-follower-read
 SELECT * FROM t AS OF SYSTEM TIME with_max_staleness('10s', true) WHERE pk = 1
 ----
 1
-events (15 found):
+events (17 found):
  * event 1: colbatchscan trace on node_idx 2: local read
  * event 2: transaction retry on node_idx: 2
  * event 3: colbatchscan trace on node_idx 2: local read
@@ -200,13 +200,15 @@ events (15 found):
  * event 12: transaction retry on node_idx: 2
  * event 13: colbatchscan trace on node_idx 2: local read
  * event 14: transaction retry on node_idx: 2
- * event 15: colbatchscan trace on node_idx 2: local follower read
+ * event 15: colbatchscan trace on node_idx 2: local read
+ * event 16: transaction retry on node_idx: 2
+ * event 17: colbatchscan trace on node_idx 2: local follower read
 
 query idx=2
 SELECT * FROM t AS OF SYSTEM TIME with_min_timestamp(now() - '10s', true) WHERE pk = 1
 ----
 1
-events (15 found):
+events (17 found):
  * event 1: colbatchscan trace on node_idx 2: local read
  * event 2: transaction retry on node_idx: 2
  * event 3: colbatchscan trace on node_idx 2: local read
@@ -221,7 +223,9 @@ events (15 found):
  * event 12: transaction retry on node_idx: 2
  * event 13: colbatchscan trace on node_idx 2: local read
  * event 14: transaction retry on node_idx: 2
- * event 15: colbatchscan trace on node_idx 2: local follower read
+ * event 15: colbatchscan trace on node_idx 2: local read
+ * event 16: transaction retry on node_idx: 2
+ * event 17: colbatchscan trace on node_idx 2: local follower read
 
 # When creating a new table, ensure when nearest_only=True, we correctly error
 # with the schema not existing if none of the followers have caught up.
diff --git a/pkg/ccl/schemachangerccl/testdata/end_to_end/create_index b/pkg/ccl/schemachangerccl/testdata/end_to_end/create_index
index c117f08847c9..9ff3905ede53 100644
--- a/pkg/ccl/schemachangerccl/testdata/end_to_end/create_index
+++ b/pkg/ccl/schemachangerccl/testdata/end_to_end/create_index
@@ -146,7 +146,7 @@ notified job registry to adopt jobs: [1]
 begin transaction #2
 commit transaction #2
 begin transaction #3
-## PostCommitPhase stage 1 of 6 with 3 MutationType ops
+## PostCommitPhase stage 1 of 7 with 3 MutationType ops
 upsert descriptor #104
   ...
      formatVersion: 3
@@ -168,14 +168,14 @@ upsert descriptor #104
      unexposedParentSchemaId: 101
   -  version: "2"
   +  version: "3"
-update progress of schema change job #1: "PostCommitPhase stage 2 of 6 with 1 BackfillType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 2 of 7 with 1 BackfillType op pending"
 commit transaction #3
 begin transaction #4
-## PostCommitPhase stage 2 of 6 with 1 BackfillType op
+## PostCommitPhase stage 2 of 7 with 1 BackfillType op
 backfill indexes [2] from index #1 in table #104
 commit transaction #4
 begin transaction #5
-## PostCommitPhase stage 3 of 6 with 3 MutationType ops
+## PostCommitPhase stage 3 of 7 with 3 MutationType ops
 upsert descriptor #104
   ...
      formatVersion: 3
@@ -197,10 +197,10 @@ upsert descriptor #104
      unexposedParentSchemaId: 101
   -  version: "3"
   +  version: "4"
-update progress of schema change job #1: "PostCommitPhase stage 4 of 6 with 1 MutationType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 4 of 7 with 1 MutationType op pending"
 commit transaction #5
 begin transaction #6
-## PostCommitPhase stage 4 of 6 with 3 MutationType ops
+## PostCommitPhase stage 4 of 7 with 3 MutationType ops
 upsert descriptor #104
   ...
      formatVersion: 3
@@ -214,7 +214,7 @@ upsert descriptor #104
          version: 4
        mutationId: 1
   -    state: DELETE_ONLY
-  +    state: DELETE_AND_WRITE_ONLY
+  +    state: MERGING
      - direction: ADD
        index:
   ...
@@ -222,17 +222,42 @@ upsert descriptor #104
      unexposedParentSchemaId: 101
   -  version: "4"
   +  version: "5"
-update progress of schema change job #1: "PostCommitPhase stage 5 of 6 with 1 BackfillType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 5 of 7 with 1 BackfillType op pending"
 commit transaction #6
 begin transaction #7
-## PostCommitPhase stage 5 of 6 with 1 BackfillType op
+## PostCommitPhase stage 5 of 7 with 1 BackfillType op
 merge temporary indexes [3] into backfilled indexes [2] in table #104
 commit transaction #7
 begin transaction #8
-## PostCommitPhase stage 6 of 6 with 1 ValidationType op
-validate forward indexes [2] in table #104
+## PostCommitPhase stage 6 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     formatVersion: 3
+     id: 104
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     mutations:
+     - direction: ADD
+  ...
+         version: 4
+       mutationId: 1
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "5"
+  +  version: "6"
+update progress of schema change job #1: "PostCommitPhase stage 7 of 7 with 1 ValidationType op pending"
 commit transaction #8
 begin transaction #9
+## PostCommitPhase stage 7 of 7 with 1 ValidationType op
+validate forward indexes [2] in table #104
+commit transaction #9
+begin transaction #10
 ## PostCommitNonRevertiblePhase stage 1 of 2 with 5 MutationType ops
 upsert descriptor #104
   ...
@@ -245,7 +270,7 @@ upsert descriptor #104
      formatVersion: 3
      id: 104
   -  modificationTime:
-  -    wallTime: "1640995200000000006"
+  -    wallTime: "1640995200000000008"
   +  indexes:
   +  - constraintId: 2
   +    createdExplicitly: true
@@ -326,12 +351,12 @@ upsert descriptor #104
   ...
        time: {}
      unexposedParentSchemaId: 101
-  -  version: "5"
-  +  version: "6"
+  -  version: "6"
+  +  version: "7"
 update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 2 of 2 with 2 MutationType ops pending"
 set schema change job #1 to non-cancellable
-commit transaction #9
-begin transaction #10
+commit transaction #10
+begin transaction #11
 ## PostCommitNonRevertiblePhase stage 2 of 2 with 4 MutationType ops
 upsert descriptor #104
   ...
@@ -358,7 +383,7 @@ upsert descriptor #104
        - money
        version: 4
   -  modificationTime:
-  -    wallTime: "1640995200000000009"
+  -    wallTime: "1640995200000000010"
   -  mutations:
   -  - direction: DROP
   -    index:
@@ -401,12 +426,12 @@ upsert descriptor #104
   ...
        time: {}
      unexposedParentSchemaId: 101
-  -  version: "6"
-  +  version: "7"
+  -  version: "7"
+  +  version: "8"
 write *eventpb.FinishSchemaChange to event log for descriptor 104
 create job #2 (non-cancelable: true): "GC for "
   descriptor IDs: [104]
 update progress of schema change job #1: "all stages completed"
-commit transaction #10
+commit transaction #11
 notified job registry to adopt jobs: [2]
 # end PostCommitPhase
diff --git a/pkg/ccl/schemachangerccl/testdata/explain/create_index b/pkg/ccl/schemachangerccl/testdata/explain/create_index
index ffa3d8a6aacb..47cdfc1f404f 100644
--- a/pkg/ccl/schemachangerccl/testdata/explain/create_index
+++ b/pkg/ccl/schemachangerccl/testdata/explain/create_index
@@ -39,40 +39,47 @@ Schema change plan for CREATE INDEX ‹id1› ON ‹defaultdb›.‹public›.
  │              ├── SetJobStateOnDescriptor {"DescriptorID":104,"Initialize":true}
  │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
  ├── PostCommitPhase
- │    ├── Stage 1 of 6 in PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
  │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
  │    │    └── 3 Mutation operations
  │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":3,"TableID":104}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 2 of 6 in PostCommitPhase
+ │    ├── Stage 2 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── BACKFILL_ONLY → BACKFILLED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 1 Backfill operation
  │    │         └── BackfillIndex {"IndexID":2,"SourceIndexID":1,"TableID":104}
- │    ├── Stage 3 of 6 in PostCommitPhase
+ │    ├── Stage 3 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── BACKFILLED → DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 3 Mutation operations
  │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":2,"TableID":104}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 4 of 6 in PostCommitPhase
+ │    ├── Stage 4 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── DELETE_ONLY → MERGE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 3 Mutation operations
- │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":2,"TableID":104}
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":2,"TableID":104}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 5 of 6 in PostCommitPhase
+ │    ├── Stage 5 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── MERGE_ONLY → MERGED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 1 Backfill operation
  │    │         └── MergeIndex {"BackfilledIndexID":2,"TableID":104,"TemporaryIndexID":3}
- │    └── Stage 6 of 6 in PostCommitPhase
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":2,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
  │         ├── 1 element transitioning toward PUBLIC
- │         │    └── MERGED → VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
+ │         │    └── WRITE_ONLY → VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
  │         └── 1 Validation operation
  │              └── ValidateUniqueIndex {"IndexID":2,"TableID":104}
  └── PostCommitNonRevertiblePhase
diff --git a/pkg/ccl/schemachangerccl/testdata/explain_verbose/create_index b/pkg/ccl/schemachangerccl/testdata/explain_verbose/create_index
index 09af851fcd07..e3482cb67a20 100644
--- a/pkg/ccl/schemachangerccl/testdata/explain_verbose/create_index
+++ b/pkg/ccl/schemachangerccl/testdata/explain_verbose/create_index
@@ -172,7 +172,7 @@ EXPLAIN (ddl, verbose) CREATE INDEX id1
 │                 DescriptorIDs:
 │                 - 104
 │                 JobID: 1
-│                 RunningStatus: PostCommitPhase stage 1 of 6 with 1 MutationType op pending
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
 │                 Statements:
 │                 - statement: CREATE INDEX id1 ON defaultdb.t1 (id, name) STORING (money) PARTITION
 │                     BY LIST (id) (PARTITION p1 VALUES IN (1))
@@ -182,7 +182,7 @@ EXPLAIN (ddl, verbose) CREATE INDEX id1
 │
 ├── • PostCommitPhase
 │   │
-│   ├── • Stage 1 of 6 in PostCommitPhase
+│   ├── • Stage 1 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
 │   │   │   │
@@ -209,9 +209,9 @@ EXPLAIN (ddl, verbose) CREATE INDEX id1
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 2 of 6 with 1 BackfillType op pending
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
 │   │
-│   ├── • Stage 2 of 6 in PostCommitPhase
+│   ├── • Stage 2 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -237,7 +237,7 @@ EXPLAIN (ddl, verbose) CREATE INDEX id1
 │   │             SourceIndexID: 1
 │   │             TableID: 104
 │   │
-│   ├── • Stage 3 of 6 in PostCommitPhase
+│   ├── • Stage 3 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -255,9 +255,9 @@ EXPLAIN (ddl, verbose) CREATE INDEX id1
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 4 of 6 with 1 MutationType op pending
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
 │   │
-│   ├── • Stage 4 of 6 in PostCommitPhase
+│   ├── • Stage 4 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -266,7 +266,7 @@ EXPLAIN (ddl, verbose) CREATE INDEX id1
 │   │   │
 │   │   └── • 3 Mutation operations
 │   │       │
-│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       ├── • MakeBackfilledIndexMerging
 │   │       │     IndexID: 2
 │   │       │     TableID: 104
 │   │       │
@@ -275,9 +275,9 @@ EXPLAIN (ddl, verbose) CREATE INDEX id1
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 5 of 6 with 1 BackfillType op pending
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
 │   │
-│   ├── • Stage 5 of 6 in PostCommitPhase
+│   ├── • Stage 5 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -291,12 +291,32 @@ EXPLAIN (ddl, verbose) CREATE INDEX id1
 │   │             TableID: 104
 │   │             TemporaryIndexID: 3
 │   │
-│   └── • Stage 6 of 6 in PostCommitPhase
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 2
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
 │       │
 │       ├── • 1 element transitioning toward PUBLIC
 │       │   │
 │       │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
-│       │         MERGED → VALIDATED
+│       │         WRITE_ONLY → VALIDATED
 │       │
 │       └── • 1 Validation operation
 │           │
diff --git a/pkg/sql/schemachanger/scexec/scmutationexec/column.go b/pkg/sql/schemachanger/scexec/scmutationexec/column.go
index 7ccb2d072a5e..316da854ecf3 100644
--- a/pkg/sql/schemachanger/scexec/scmutationexec/column.go
+++ b/pkg/sql/schemachanger/scexec/scmutationexec/column.go
@@ -12,6 +12,7 @@ package scmutationexec
 
 import (
 	"context"
+	"sort"
 
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
@@ -118,6 +119,18 @@ func (m *visitor) MakeColumnPublic(ctx context.Context, op scop.MakeColumnPublic
 	// that okay?
 	tbl.Columns = append(tbl.Columns,
 		*(protoutil.Clone(mut.GetColumn())).(*descpb.ColumnDescriptor))
+
+	// Ensure that the column is added in the right location. This is important
+	// when rolling back dropped columns.
+	getID := func(col *descpb.ColumnDescriptor) int {
+		if col.PGAttributeNum != 0 {
+			return int(col.PGAttributeNum)
+		}
+		return int(col.ID)
+	}
+	sort.Slice(tbl.Columns, func(i, j int) bool {
+		return getID(&tbl.Columns[i]) < getID(&tbl.Columns[j])
+	})
 	return nil
 }
 
diff --git a/pkg/sql/schemachanger/scexec/scmutationexec/index.go b/pkg/sql/schemachanger/scexec/scmutationexec/index.go
index 537c94c678ce..f3c6f3fc45c9 100644
--- a/pkg/sql/schemachanger/scexec/scmutationexec/index.go
+++ b/pkg/sql/schemachanger/scexec/scmutationexec/index.go
@@ -142,6 +142,38 @@ func (m *visitor) MakeAddedIndexDeleteAndWriteOnly(
 	)
 }
 
+func (m *visitor) MakeBackfilledIndexMerging(
+	ctx context.Context, op scop.MakeBackfilledIndexMerging,
+) error {
+	tbl, err := m.checkOutTable(ctx, op.TableID)
+	if err != nil {
+		return err
+	}
+	return mutationStateChange(
+		tbl,
+		MakeIndexIDMutationSelector(op.IndexID),
+		descpb.DescriptorMutation_DELETE_ONLY,
+		descpb.DescriptorMutation_MERGING,
+		descpb.DescriptorMutation_ADD,
+	)
+}
+
+func (m *visitor) MakeMergedIndexWriteOnly(
+	ctx context.Context, op scop.MakeMergedIndexWriteOnly,
+) error {
+	tbl, err := m.checkOutTable(ctx, op.TableID)
+	if err != nil {
+		return err
+	}
+	return mutationStateChange(
+		tbl,
+		MakeIndexIDMutationSelector(op.IndexID),
+		descpb.DescriptorMutation_MERGING,
+		descpb.DescriptorMutation_DELETE_AND_WRITE_ONLY,
+		descpb.DescriptorMutation_ADD,
+	)
+}
+
 func (m *visitor) MakeAddedPrimaryIndexPublic(
 	ctx context.Context, op scop.MakeAddedPrimaryIndexPublic,
 ) error {
@@ -234,11 +266,19 @@ func (m *visitor) MakeDroppedIndexDeleteOnly(
 	if err != nil {
 		return err
 	}
+	idx, err := tbl.FindIndexWithID(op.IndexID)
+	if err != nil {
+		return err
+	}
+	// It's okay if the index is in MERGING.
+	exp := descpb.DescriptorMutation_DELETE_AND_WRITE_ONLY
+	if idx.Merging() {
+		exp = descpb.DescriptorMutation_MERGING
+	}
 	return mutationStateChange(
 		tbl,
 		MakeIndexIDMutationSelector(op.IndexID),
-		descpb.DescriptorMutation_DELETE_AND_WRITE_ONLY,
-		descpb.DescriptorMutation_DELETE_ONLY,
+		exp, descpb.DescriptorMutation_DELETE_ONLY,
 		descpb.DescriptorMutation_DROP,
 	)
 }
diff --git a/pkg/sql/schemachanger/scop/mutation.go b/pkg/sql/schemachanger/scop/mutation.go
index bb9ec7e23dc1..95ace62c59c2 100644
--- a/pkg/sql/schemachanger/scop/mutation.go
+++ b/pkg/sql/schemachanger/scop/mutation.go
@@ -76,6 +76,22 @@ type MakeAddedIndexDeleteAndWriteOnly struct {
 	IndexID descpb.IndexID
 }
 
+// MakeBackfilledIndexMerging transitions an index addition mutation from
+// DELETE_ONLY to MERGING.
+type MakeBackfilledIndexMerging struct {
+	mutationOp
+	TableID descpb.ID
+	IndexID descpb.IndexID
+}
+
+// MakeMergedIndexWriteOnly transitions an index addition mutation from
+// MERGING to WRITE_ONLY.
+type MakeMergedIndexWriteOnly struct {
+	mutationOp
+	TableID descpb.ID
+	IndexID descpb.IndexID
+}
+
 // MakeBackfillingIndexDeleteOnly transitions an index addition mutation from
 // BACKFILLING to DELETE_ONLY.
 type MakeBackfillingIndexDeleteOnly struct {
diff --git a/pkg/sql/schemachanger/scop/mutation_visitor_generated.go b/pkg/sql/schemachanger/scop/mutation_visitor_generated.go
index e91c577fd3ca..fda175f4a341 100644
--- a/pkg/sql/schemachanger/scop/mutation_visitor_generated.go
+++ b/pkg/sql/schemachanger/scop/mutation_visitor_generated.go
@@ -27,6 +27,8 @@ type MutationVisitor interface {
 	MakeAddedIndexBackfilling(context.Context, MakeAddedIndexBackfilling) error
 	SetAddedIndexPartialPredicate(context.Context, SetAddedIndexPartialPredicate) error
 	MakeAddedIndexDeleteAndWriteOnly(context.Context, MakeAddedIndexDeleteAndWriteOnly) error
+	MakeBackfilledIndexMerging(context.Context, MakeBackfilledIndexMerging) error
+	MakeMergedIndexWriteOnly(context.Context, MakeMergedIndexWriteOnly) error
 	MakeBackfillingIndexDeleteOnly(context.Context, MakeBackfillingIndexDeleteOnly) error
 	MakeAddedSecondaryIndexPublic(context.Context, MakeAddedSecondaryIndexPublic) error
 	MakeAddedPrimaryIndexPublic(context.Context, MakeAddedPrimaryIndexPublic) error
@@ -120,6 +122,16 @@ func (op MakeAddedIndexDeleteAndWriteOnly) Visit(ctx context.Context, v Mutation
 	return v.MakeAddedIndexDeleteAndWriteOnly(ctx, op)
 }
 
+// Visit is part of the MutationOp interface.
+func (op MakeBackfilledIndexMerging) Visit(ctx context.Context, v MutationVisitor) error {
+	return v.MakeBackfilledIndexMerging(ctx, op)
+}
+
+// Visit is part of the MutationOp interface.
+func (op MakeMergedIndexWriteOnly) Visit(ctx context.Context, v MutationVisitor) error {
+	return v.MakeMergedIndexWriteOnly(ctx, op)
+}
+
 // Visit is part of the MutationOp interface.
 func (op MakeBackfillingIndexDeleteOnly) Visit(ctx context.Context, v MutationVisitor) error {
 	return v.MakeBackfillingIndexDeleteOnly(ctx, op)
diff --git a/pkg/sql/schemachanger/scplan/internal/opgen/opgen_primary_index.go b/pkg/sql/schemachanger/scplan/internal/opgen/opgen_primary_index.go
index d46620e4e798..7cb9cd39cbf9 100644
--- a/pkg/sql/schemachanger/scplan/internal/opgen/opgen_primary_index.go
+++ b/pkg/sql/schemachanger/scplan/internal/opgen/opgen_primary_index.go
@@ -45,14 +45,13 @@ func init() {
 				}),
 			),
 			to(scpb.Status_MERGE_ONLY,
-				emit(func(this *scpb.PrimaryIndex) *scop.MakeAddedIndexDeleteAndWriteOnly {
-					return &scop.MakeAddedIndexDeleteAndWriteOnly{
+				emit(func(this *scpb.PrimaryIndex) *scop.MakeBackfilledIndexMerging {
+					return &scop.MakeBackfilledIndexMerging{
 						TableID: this.TableID,
 						IndexID: this.IndexID,
 					}
 				}),
 			),
-			equiv(scpb.Status_WRITE_ONLY),
 			to(scpb.Status_MERGED,
 				emit(func(this *scpb.PrimaryIndex) *scop.MergeIndex {
 					return &scop.MergeIndex{
@@ -62,6 +61,20 @@ func init() {
 					}
 				}),
 			),
+			// The transition from MERGED to WRITE_ONLY must precede index validation.
+			// In MERGE_ONLY and MERGED, the index receives writes, but writes do not
+			// enforce uniqueness (they don't use CPut, see ForcePut). In WRITE_ONLY,
+			// the index receives normal writes. Only once writes are enforcing the
+			// uniqueness constraint for new can we validate that the index does
+			// indeed represent a valid uniqueness constraint over all rows.
+			to(scpb.Status_WRITE_ONLY,
+				emit(func(this *scpb.PrimaryIndex) *scop.MakeMergedIndexWriteOnly {
+					return &scop.MakeMergedIndexWriteOnly{
+						TableID: this.TableID,
+						IndexID: this.IndexID,
+					}
+				}),
+			),
 			to(scpb.Status_VALIDATED,
 				emit(func(this *scpb.PrimaryIndex) *scop.ValidateUniqueIndex {
 					return &scop.ValidateUniqueIndex{
diff --git a/pkg/sql/schemachanger/scplan/internal/opgen/opgen_secondary_index.go b/pkg/sql/schemachanger/scplan/internal/opgen/opgen_secondary_index.go
index 054c51664508..f1667efacb53 100644
--- a/pkg/sql/schemachanger/scplan/internal/opgen/opgen_secondary_index.go
+++ b/pkg/sql/schemachanger/scplan/internal/opgen/opgen_secondary_index.go
@@ -46,14 +46,13 @@ func init() {
 				}),
 			),
 			to(scpb.Status_MERGE_ONLY,
-				emit(func(this *scpb.SecondaryIndex) *scop.MakeAddedIndexDeleteAndWriteOnly {
-					return &scop.MakeAddedIndexDeleteAndWriteOnly{
+				emit(func(this *scpb.SecondaryIndex) *scop.MakeBackfilledIndexMerging {
+					return &scop.MakeBackfilledIndexMerging{
 						TableID: this.TableID,
 						IndexID: this.IndexID,
 					}
 				}),
 			),
-			equiv(scpb.Status_WRITE_ONLY),
 			to(scpb.Status_MERGED,
 				emit(func(this *scpb.SecondaryIndex) *scop.MergeIndex {
 					return &scop.MergeIndex{
@@ -63,6 +62,20 @@ func init() {
 					}
 				}),
 			),
+			// The transition from MERGED to WRITE_ONLY must precede index validation.
+			// In MERGE_ONLY and MERGED, the index receives writes, but writes do not
+			// enforce uniqueness (they don't use CPut, see ForcePut). In WRITE_ONLY,
+			// the index receives normal writes. Only once writes are enforcing the
+			// uniqueness constraint for new can we validate that the index does
+			// indeed represent a valid uniqueness constraint over all rows.
+			to(scpb.Status_WRITE_ONLY,
+				emit(func(this *scpb.SecondaryIndex) *scop.MakeMergedIndexWriteOnly {
+					return &scop.MakeMergedIndexWriteOnly{
+						TableID: this.TableID,
+						IndexID: this.IndexID,
+					}
+				}),
+			),
 			to(scpb.Status_VALIDATED,
 				emit(func(this *scpb.SecondaryIndex) *scop.ValidateUniqueIndex {
 					// TODO(ajwerner): Should this say something other than
diff --git a/pkg/sql/schemachanger/scplan/internal/rules/dep_index_and_column.go b/pkg/sql/schemachanger/scplan/internal/rules/dep_index_and_column.go
index e857c703b18b..cc8713ce3419 100644
--- a/pkg/sql/schemachanger/scplan/internal/rules/dep_index_and_column.go
+++ b/pkg/sql/schemachanger/scplan/internal/rules/dep_index_and_column.go
@@ -497,6 +497,32 @@ func init() {
 		},
 	)
 
+	// Without this rule, we might have an index which exists and contains
+	// a column which does not exist. This would lead to panics inside the
+	// optimizer and an invalid table descriptor.
+	registerDepRule("indexes containing columns reach absent before column",
+		scgraph.Precedence,
+		"index", "column",
+		func(from, to nodeVars) rel.Clauses {
+			ct := rel.Var("column-type")
+			return rel.Clauses{
+				from.el.Type((*scpb.PrimaryIndex)(nil), (*scpb.SecondaryIndex)(nil)),
+				to.el.Type((*scpb.Column)(nil)),
+				indexContainsColumn(
+					from.el, to.el, "index-column", "table-id", "column-id", "index-id",
+				),
+				ct.Type((*scpb.ColumnType)(nil)),
+				joinOnColumnID(to.el, ct, "table-id", "column-id"),
+				targetStatusEq(from.target, to.target, scpb.ToAbsent),
+				currentStatusEq(from.node, to.node, scpb.Status_ABSENT),
+				rel.Filter("columnTypeIsNotBeingDropped", ct)(func(
+					ct *scpb.ColumnType,
+				) bool {
+					return !ct.IsRelationBeingDropped
+				}),
+			}
+		})
+
 	registerDepRule(
 		"partial predicate removed right before secondary index when not dropping relation",
 		scgraph.SameStagePrecedence,
@@ -518,22 +544,24 @@ func init() {
 	)
 }
 
+var indexContainsColumn = screl.Schema.Def6(
+	"indexContainsColumn",
+	"index", "column", "index-column", "table-id", "column-id", "index-id", func(
+		index, column, indexColumn, tableID, columnID, indexID rel.Var,
+	) rel.Clauses {
+		return rel.Clauses{
+			index.AttrEqVar(screl.IndexID, indexID),
+			indexColumn.Type((*scpb.IndexColumn)(nil)),
+			indexColumn.AttrEqVar(screl.DescID, rel.Blank),
+			joinOnColumnID(column, indexColumn, tableID, columnID),
+			joinOnIndexID(index, indexColumn, tableID, indexID),
+		}
+	})
+
 // These rules ensure that columns and indexes containing these columns
 // appear into existence in the correct order.
 func init() {
-	indexContainsColumn := screl.Schema.Def6(
-		"indexContainsColumn",
-		"index", "column", "index-column", "table-id", "column-id", "index-id", func(
-			index, column, indexColumn, tableID, columnID, indexID rel.Var,
-		) rel.Clauses {
-			return rel.Clauses{
-				index.AttrEqVar(screl.IndexID, indexID),
-				indexColumn.Type((*scpb.IndexColumn)(nil)),
-				indexColumn.AttrEqVar(screl.DescID, rel.Blank),
-				joinOnColumnID(column, indexColumn, tableID, columnID),
-				joinOnIndexID(index, indexColumn, tableID, indexID),
-			}
-		})
+
 	sourceIndexNotSet := screl.Schema.Def1("sourceIndexNotSet", "index", func(
 		index rel.Var,
 	) rel.Clauses {
@@ -554,7 +582,7 @@ func init() {
 			}
 		})
 	registerDepRule(
-		"column depends on primary index",
+		"adding column depends on primary index",
 		scgraph.Precedence,
 		"index", "column",
 		func(from, to nodeVars) rel.Clauses {
@@ -566,7 +594,7 @@ func init() {
 					from.el, to.el, "index-column", "table-id", "column-id", "index-id",
 				),
 				targetStatusEq(from.target, to.target, scpb.ToPublic),
-				status.In(scpb.Status_WRITE_ONLY, scpb.Status_PUBLIC),
+				status.In(scpb.Status_PUBLIC),
 				status.Entities(screl.CurrentStatus, from.node, to.node),
 			}
 		},
@@ -784,6 +812,29 @@ func init() {
 				}),
 			}
 		})
+
+	// We need to ensure that the temporary index has all the relevant writes
+	// to any columns it contains. We ensure elsewhere that any index which
+	// will later be merged with the temporary index is not backfilled until
+	// that temporary index is receiving writes. This rule ensures that those
+	// write operations contain data for all columns.
+	registerDepRule(
+		"column is WRITE_ONLY before temporary index is WRITE_ONLY",
+		scgraph.Precedence,
+		"column", "index",
+		func(from, to nodeVars) rel.Clauses {
+			return rel.Clauses{
+				from.el.Type((*scpb.Column)(nil)),
+				to.el.Type((*scpb.TemporaryIndex)(nil)),
+				indexContainsColumn(to.el, from.el, "index-column", "table-id", "column-id", "index-id"),
+				targetStatus(from.target, scpb.ToPublic),
+				targetStatus(to.target, scpb.Transient),
+				currentStatus(from.node, scpb.Status_WRITE_ONLY),
+				currentStatus(to.node, scpb.Status_WRITE_ONLY),
+			}
+		},
+	)
+
 }
 
 // This rule ensures that columns depend on each other in increasing order.
diff --git a/pkg/sql/schemachanger/scplan/internal/rules/testdata/deprules b/pkg/sql/schemachanger/scplan/internal/rules/testdata/deprules
index 8d21421dd7dc..a2e3c6eea81f 100644
--- a/pkg/sql/schemachanger/scplan/internal/rules/testdata/deprules
+++ b/pkg/sql/schemachanger/scplan/internal/rules/testdata/deprules
@@ -29,6 +29,12 @@ joinOnColumnID(a, b, desc-id, col-id):
     - joinOnDescID($a, $b, $desc-id)
     - $a[ColumnID] = $col-id
     - $b[ColumnID] = $col-id
+indexContainsColumn(index, column, index-column, table-id, column-id, index-id):
+    - $index[IndexID] = $index-id
+    - $index-column[Type] = '*scpb.IndexColumn'
+    - $index-column[DescID] = $_
+    - joinOnColumnID($column, $index-column, $table-id, $column-id)
+    - joinOnIndexID($index, $index-column, $table-id, $index-id)
 joinOnConstraintID(a, b, desc-id, constraint-id):
     - joinOnDescID($a, $b, $desc-id)
     - $a[ConstraintID] = $constraint-id
@@ -37,12 +43,6 @@ index-dependents(index, dep, table-id, index-id):
     - $dep[Type] IN ['*scpb.IndexName', '*scpb.IndexPartitioning', '*scpb.SecondaryIndexPartial', '*scpb.IndexComment', '*scpb.IndexColumn']
     - $index[Type] IN ['*scpb.PrimaryIndex', '*scpb.TemporaryIndex', '*scpb.SecondaryIndex']
     - joinOnIndexID($dep, $index, $table-id, $index-id)
-indexContainsColumn(index, column, index-column, table-id, column-id, index-id):
-    - $index[IndexID] = $index-id
-    - $index-column[Type] = '*scpb.IndexColumn'
-    - $index-column[DescID] = $_
-    - joinOnColumnID($column, $index-column, $table-id, $column-id)
-    - joinOnIndexID($index, $index-column, $table-id, $index-id)
 sourceIndexNotSet(index):
     - $index[SourceIndexID] != 0
 columnInPrimaryIndexSwap(index, column, index-column, table-id, column-id, index-id):
@@ -418,6 +418,23 @@ deprules
     - columnTypeIsNotBeingDropped(*scpb.ColumnType)($column-type)
     - joinTargetNode($column-type, $column-type-target, $column-type-node)
     - joinTargetNode($column, $column-target, $column-node)
+- name: indexes containing columns reach absent before column
+  from: index-node
+  kind: Precedence
+  to: column-node
+  query:
+    - $index[Type] IN ['*scpb.PrimaryIndex', '*scpb.SecondaryIndex']
+    - $column[Type] = '*scpb.Column'
+    - indexContainsColumn($index, $column, $index-column, $table-id, $column-id, $index-id)
+    - $column-type[Type] = '*scpb.ColumnType'
+    - joinOnColumnID($column, $column-type, $table-id, $column-id)
+    - $index-target[TargetStatus] = ABSENT
+    - $column-target[TargetStatus] = ABSENT
+    - $index-node[CurrentStatus] = ABSENT
+    - $column-node[CurrentStatus] = ABSENT
+    - columnTypeIsNotBeingDropped(*scpb.ColumnType)($column-type)
+    - joinTargetNode($index, $index-target, $index-node)
+    - joinTargetNode($column, $column-target, $column-node)
 - name: partial predicate removed right before secondary index when not dropping relation
   from: partial-predicate-node
   kind: SameStagePrecedence
@@ -433,7 +450,7 @@ deprules
     - secondaryIndexPartialIsNotBeingDropped(*scpb.SecondaryIndexPartial)($partial-predicate)
     - joinTargetNode($partial-predicate, $partial-predicate-target, $partial-predicate-node)
     - joinTargetNode($index, $index-target, $index-node)
-- name: column depends on primary index
+- name: adding column depends on primary index
   from: index-node
   kind: Precedence
   to: column-node
@@ -443,7 +460,7 @@ deprules
     - columnInPrimaryIndexSwap($index, $column, $index-column, $table-id, $column-id, $index-id)
     - $index-target[TargetStatus] = PUBLIC
     - $column-target[TargetStatus] = PUBLIC
-    - $status IN [WRITE_ONLY, PUBLIC]
+    - $status IN [PUBLIC]
     - $index-node[CurrentStatus] = $status
     - $column-node[CurrentStatus] = $status
     - joinTargetNode($index, $index-target, $index-node)
@@ -621,6 +638,20 @@ deprules
     - indexes-id-less(scpb.Element, scpb.Element)($a, $b)
     - joinTargetNode($index-a, $index-a-target, $index-a-node)
     - joinTargetNode($index-b, $index-b-target, $index-b-node)
+- name: column is WRITE_ONLY before temporary index is WRITE_ONLY
+  from: column-node
+  kind: Precedence
+  to: index-node
+  query:
+    - $column[Type] = '*scpb.Column'
+    - $index[Type] = '*scpb.TemporaryIndex'
+    - indexContainsColumn($index, $column, $index-column, $table-id, $column-id, $index-id)
+    - $column-target[TargetStatus] = PUBLIC
+    - $index-target[TargetStatus] = TRANSIENT_ABSENT
+    - $column-node[CurrentStatus] = WRITE_ONLY
+    - $index-node[CurrentStatus] = WRITE_ONLY
+    - joinTargetNode($column, $column-target, $column-node)
+    - joinTargetNode($index, $index-target, $index-node)
 - name: ensure columns are in increasing order
   from: later-column-node
   kind: SameStagePrecedence
diff --git a/pkg/sql/schemachanger/scplan/internal/rules/testdata/oprules b/pkg/sql/schemachanger/scplan/internal/rules/testdata/oprules
index f8848e4b63a0..bd2a0fa119ac 100644
--- a/pkg/sql/schemachanger/scplan/internal/rules/testdata/oprules
+++ b/pkg/sql/schemachanger/scplan/internal/rules/testdata/oprules
@@ -29,6 +29,12 @@ joinOnColumnID(a, b, desc-id, col-id):
     - joinOnDescID($a, $b, $desc-id)
     - $a[ColumnID] = $col-id
     - $b[ColumnID] = $col-id
+indexContainsColumn(index, column, index-column, table-id, column-id, index-id):
+    - $index[IndexID] = $index-id
+    - $index-column[Type] = '*scpb.IndexColumn'
+    - $index-column[DescID] = $_
+    - joinOnColumnID($column, $index-column, $table-id, $column-id)
+    - joinOnIndexID($index, $index-column, $table-id, $index-id)
 joinOnConstraintID(a, b, desc-id, constraint-id):
     - joinOnDescID($a, $b, $desc-id)
     - $a[ConstraintID] = $constraint-id
@@ -37,12 +43,6 @@ index-dependents(index, dep, table-id, index-id):
     - $dep[Type] IN ['*scpb.IndexName', '*scpb.IndexPartitioning', '*scpb.SecondaryIndexPartial', '*scpb.IndexComment', '*scpb.IndexColumn']
     - $index[Type] IN ['*scpb.PrimaryIndex', '*scpb.TemporaryIndex', '*scpb.SecondaryIndex']
     - joinOnIndexID($dep, $index, $table-id, $index-id)
-indexContainsColumn(index, column, index-column, table-id, column-id, index-id):
-    - $index[IndexID] = $index-id
-    - $index-column[Type] = '*scpb.IndexColumn'
-    - $index-column[DescID] = $_
-    - joinOnColumnID($column, $index-column, $table-id, $column-id)
-    - joinOnIndexID($index, $index-column, $table-id, $index-id)
 sourceIndexNotSet(index):
     - $index[SourceIndexID] != 0
 columnInPrimaryIndexSwap(index, column, index-column, table-id, column-id, index-id):
diff --git a/pkg/sql/schemachanger/scplan/testdata/alter_table b/pkg/sql/schemachanger/scplan/testdata/alter_table
index 2fab13926bfd..9d43f4179814 100644
--- a/pkg/sql/schemachanger/scplan/testdata/alter_table
+++ b/pkg/sql/schemachanger/scplan/testdata/alter_table
@@ -232,13 +232,13 @@ PreCommitPhase stage 1 of 1 with 2 MutationType ops
       DescriptorIDs:
       - 104
       JobID: 1
-      RunningStatus: PostCommitPhase stage 1 of 6 with 2 MutationType ops pending
+      RunningStatus: PostCommitPhase stage 1 of 7 with 2 MutationType ops pending
       Statements:
       - statement: ALTER TABLE defaultdb.foo ADD COLUMN j INT8 DEFAULT 123
         redactedstatement: ALTER TABLE ‹defaultdb›.public.‹foo› ADD COLUMN ‹j› INT8 DEFAULT
           ‹123›
         statementtag: ALTER TABLE
-PostCommitPhase stage 1 of 6 with 4 MutationType ops
+PostCommitPhase stage 1 of 7 with 4 MutationType ops
   transitions:
     [[Column:{DescID: 104, ColumnID: 2}, PUBLIC], DELETE_ONLY] -> WRITE_ONLY
     [[TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}, TRANSIENT_ABSENT], DELETE_ONLY] -> WRITE_ONLY
@@ -253,7 +253,7 @@ PostCommitPhase stage 1 of 6 with 4 MutationType ops
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 2 of 6 with 1 BackfillType op
+PostCommitPhase stage 2 of 7 with 1 BackfillType op
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], BACKFILL_ONLY] -> BACKFILLED
   ops:
@@ -261,7 +261,7 @@ PostCommitPhase stage 2 of 6 with 1 BackfillType op
       IndexID: 2
       SourceIndexID: 1
       TableID: 104
-PostCommitPhase stage 3 of 6 with 3 MutationType ops
+PostCommitPhase stage 3 of 7 with 3 MutationType ops
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], BACKFILLED] -> DELETE_ONLY
   ops:
@@ -272,18 +272,18 @@ PostCommitPhase stage 3 of 6 with 3 MutationType ops
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 4 of 6 with 3 MutationType ops
+PostCommitPhase stage 4 of 7 with 3 MutationType ops
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], DELETE_ONLY] -> MERGE_ONLY
   ops:
-    *scop.MakeAddedIndexDeleteAndWriteOnly
+    *scop.MakeBackfilledIndexMerging
       IndexID: 2
       TableID: 104
     *scop.SetJobStateOnDescriptor
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 5 of 6 with 1 BackfillType op
+PostCommitPhase stage 5 of 7 with 1 BackfillType op
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGE_ONLY] -> MERGED
   ops:
@@ -291,9 +291,20 @@ PostCommitPhase stage 5 of 6 with 1 BackfillType op
       BackfilledIndexID: 2
       TableID: 104
       TemporaryIndexID: 3
-PostCommitPhase stage 6 of 6 with 1 ValidationType op
+PostCommitPhase stage 6 of 7 with 3 MutationType ops
+  transitions:
+    [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGED] -> WRITE_ONLY
+  ops:
+    *scop.MakeMergedIndexWriteOnly
+      IndexID: 2
+      TableID: 104
+    *scop.SetJobStateOnDescriptor
+      DescriptorID: 104
+    *scop.UpdateSchemaChangerJob
+      JobID: 1
+PostCommitPhase stage 7 of 7 with 1 ValidationType op
   transitions:
-    [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGED] -> VALIDATED
+    [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], WRITE_ONLY] -> VALIDATED
   ops:
     *scop.ValidateUniqueIndex
       IndexID: 2
@@ -562,7 +573,7 @@ PreCommitPhase stage 1 of 1 with 2 MutationType ops
       DescriptorIDs:
       - 104
       JobID: 1
-      RunningStatus: PostCommitPhase stage 1 of 6 with 3 MutationType ops pending
+      RunningStatus: PostCommitPhase stage 1 of 7 with 3 MutationType ops pending
       Statements:
       - statement: ALTER TABLE defaultdb.foo ADD COLUMN j INT8 DEFAULT 123
         redactedstatement: ALTER TABLE ‹defaultdb›.public.‹foo› ADD COLUMN ‹j› INT8 DEFAULT
@@ -572,7 +583,7 @@ PreCommitPhase stage 1 of 1 with 2 MutationType ops
         redactedstatement: ALTER TABLE ‹defaultdb›.public.‹foo› ADD COLUMN ‹k› INT8 DEFAULT
           ‹456›
         statementtag: ALTER TABLE
-PostCommitPhase stage 1 of 6 with 5 MutationType ops
+PostCommitPhase stage 1 of 7 with 5 MutationType ops
   transitions:
     [[Column:{DescID: 104, ColumnID: 2}, PUBLIC], DELETE_ONLY] -> WRITE_ONLY
     [[TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}, TRANSIENT_ABSENT], DELETE_ONLY] -> WRITE_ONLY
@@ -581,17 +592,17 @@ PostCommitPhase stage 1 of 6 with 5 MutationType ops
     *scop.MakeAddedColumnDeleteAndWriteOnly
       ColumnID: 2
       TableID: 104
-    *scop.MakeAddedIndexDeleteAndWriteOnly
-      IndexID: 3
-      TableID: 104
     *scop.MakeAddedColumnDeleteAndWriteOnly
       ColumnID: 3
       TableID: 104
+    *scop.MakeAddedIndexDeleteAndWriteOnly
+      IndexID: 3
+      TableID: 104
     *scop.SetJobStateOnDescriptor
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 2 of 6 with 1 BackfillType op
+PostCommitPhase stage 2 of 7 with 1 BackfillType op
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], BACKFILL_ONLY] -> BACKFILLED
   ops:
@@ -599,7 +610,7 @@ PostCommitPhase stage 2 of 6 with 1 BackfillType op
       IndexID: 2
       SourceIndexID: 1
       TableID: 104
-PostCommitPhase stage 3 of 6 with 3 MutationType ops
+PostCommitPhase stage 3 of 7 with 3 MutationType ops
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], BACKFILLED] -> DELETE_ONLY
   ops:
@@ -610,18 +621,18 @@ PostCommitPhase stage 3 of 6 with 3 MutationType ops
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 4 of 6 with 3 MutationType ops
+PostCommitPhase stage 4 of 7 with 3 MutationType ops
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], DELETE_ONLY] -> MERGE_ONLY
   ops:
-    *scop.MakeAddedIndexDeleteAndWriteOnly
+    *scop.MakeBackfilledIndexMerging
       IndexID: 2
       TableID: 104
     *scop.SetJobStateOnDescriptor
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 5 of 6 with 1 BackfillType op
+PostCommitPhase stage 5 of 7 with 1 BackfillType op
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGE_ONLY] -> MERGED
   ops:
@@ -629,9 +640,20 @@ PostCommitPhase stage 5 of 6 with 1 BackfillType op
       BackfilledIndexID: 2
       TableID: 104
       TemporaryIndexID: 3
-PostCommitPhase stage 6 of 6 with 1 ValidationType op
+PostCommitPhase stage 6 of 7 with 3 MutationType ops
   transitions:
-    [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGED] -> VALIDATED
+    [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGED] -> WRITE_ONLY
+  ops:
+    *scop.MakeMergedIndexWriteOnly
+      IndexID: 2
+      TableID: 104
+    *scop.SetJobStateOnDescriptor
+      DescriptorID: 104
+    *scop.UpdateSchemaChangerJob
+      JobID: 1
+PostCommitPhase stage 7 of 7 with 1 ValidationType op
+  transitions:
+    [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], WRITE_ONLY] -> VALIDATED
   ops:
     *scop.ValidateUniqueIndex
       IndexID: 2
@@ -851,13 +873,13 @@ PreCommitPhase stage 1 of 1 with 2 MutationType ops
       DescriptorIDs:
       - 104
       JobID: 1
-      RunningStatus: PostCommitPhase stage 1 of 6 with 2 MutationType ops pending
+      RunningStatus: PostCommitPhase stage 1 of 7 with 2 MutationType ops pending
       Statements:
       - statement: ALTER TABLE defaultdb.foo ADD COLUMN a INT8 AS (i + 1) STORED
         redactedstatement: ALTER TABLE ‹defaultdb›.public.‹foo› ADD COLUMN ‹a› INT8 AS (‹i›
           + ‹1›) STORED
         statementtag: ALTER TABLE
-PostCommitPhase stage 1 of 6 with 4 MutationType ops
+PostCommitPhase stage 1 of 7 with 4 MutationType ops
   transitions:
     [[Column:{DescID: 104, ColumnID: 2}, PUBLIC], DELETE_ONLY] -> WRITE_ONLY
     [[TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}, TRANSIENT_ABSENT], DELETE_ONLY] -> WRITE_ONLY
@@ -872,7 +894,7 @@ PostCommitPhase stage 1 of 6 with 4 MutationType ops
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 2 of 6 with 1 BackfillType op
+PostCommitPhase stage 2 of 7 with 1 BackfillType op
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], BACKFILL_ONLY] -> BACKFILLED
   ops:
@@ -880,7 +902,7 @@ PostCommitPhase stage 2 of 6 with 1 BackfillType op
       IndexID: 2
       SourceIndexID: 1
       TableID: 104
-PostCommitPhase stage 3 of 6 with 3 MutationType ops
+PostCommitPhase stage 3 of 7 with 3 MutationType ops
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], BACKFILLED] -> DELETE_ONLY
   ops:
@@ -891,18 +913,18 @@ PostCommitPhase stage 3 of 6 with 3 MutationType ops
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 4 of 6 with 3 MutationType ops
+PostCommitPhase stage 4 of 7 with 3 MutationType ops
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], DELETE_ONLY] -> MERGE_ONLY
   ops:
-    *scop.MakeAddedIndexDeleteAndWriteOnly
+    *scop.MakeBackfilledIndexMerging
       IndexID: 2
       TableID: 104
     *scop.SetJobStateOnDescriptor
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 5 of 6 with 1 BackfillType op
+PostCommitPhase stage 5 of 7 with 1 BackfillType op
   transitions:
     [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGE_ONLY] -> MERGED
   ops:
@@ -910,9 +932,20 @@ PostCommitPhase stage 5 of 6 with 1 BackfillType op
       BackfilledIndexID: 2
       TableID: 104
       TemporaryIndexID: 3
-PostCommitPhase stage 6 of 6 with 1 ValidationType op
+PostCommitPhase stage 6 of 7 with 3 MutationType ops
+  transitions:
+    [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGED] -> WRITE_ONLY
+  ops:
+    *scop.MakeMergedIndexWriteOnly
+      IndexID: 2
+      TableID: 104
+    *scop.SetJobStateOnDescriptor
+      DescriptorID: 104
+    *scop.UpdateSchemaChangerJob
+      JobID: 1
+PostCommitPhase stage 7 of 7 with 1 ValidationType op
   transitions:
-    [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGED] -> VALIDATED
+    [[PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], WRITE_ONLY] -> VALIDATED
   ops:
     *scop.ValidateUniqueIndex
       IndexID: 2
diff --git a/pkg/sql/schemachanger/scplan/testdata/create_index b/pkg/sql/schemachanger/scplan/testdata/create_index
index f3b7e87c4fbd..7053750f5f59 100644
--- a/pkg/sql/schemachanger/scplan/testdata/create_index
+++ b/pkg/sql/schemachanger/scplan/testdata/create_index
@@ -69,13 +69,13 @@ PreCommitPhase stage 1 of 1 with 2 MutationType ops
       DescriptorIDs:
       - 104
       JobID: 1
-      RunningStatus: PostCommitPhase stage 1 of 6 with 1 MutationType op pending
+      RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
       Statements:
       - statement: CREATE INDEX id1 ON defaultdb.t1 (id, name) STORING (money)
         redactedstatement: CREATE INDEX ‹id1› ON ‹defaultdb›.public.‹t1› (‹id›, ‹name›)
           STORING (‹money›)
         statementtag: CREATE INDEX
-PostCommitPhase stage 1 of 6 with 3 MutationType ops
+PostCommitPhase stage 1 of 7 with 3 MutationType ops
   transitions:
     [[TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}, TRANSIENT_ABSENT], DELETE_ONLY] -> WRITE_ONLY
   ops:
@@ -86,7 +86,7 @@ PostCommitPhase stage 1 of 6 with 3 MutationType ops
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 2 of 6 with 1 BackfillType op
+PostCommitPhase stage 2 of 7 with 1 BackfillType op
   transitions:
     [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], BACKFILL_ONLY] -> BACKFILLED
   ops:
@@ -94,7 +94,7 @@ PostCommitPhase stage 2 of 6 with 1 BackfillType op
       IndexID: 2
       SourceIndexID: 1
       TableID: 104
-PostCommitPhase stage 3 of 6 with 3 MutationType ops
+PostCommitPhase stage 3 of 7 with 3 MutationType ops
   transitions:
     [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], BACKFILLED] -> DELETE_ONLY
   ops:
@@ -105,18 +105,18 @@ PostCommitPhase stage 3 of 6 with 3 MutationType ops
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 4 of 6 with 3 MutationType ops
+PostCommitPhase stage 4 of 7 with 3 MutationType ops
   transitions:
     [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], DELETE_ONLY] -> MERGE_ONLY
   ops:
-    *scop.MakeAddedIndexDeleteAndWriteOnly
+    *scop.MakeBackfilledIndexMerging
       IndexID: 2
       TableID: 104
     *scop.SetJobStateOnDescriptor
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 5 of 6 with 1 BackfillType op
+PostCommitPhase stage 5 of 7 with 1 BackfillType op
   transitions:
     [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGE_ONLY] -> MERGED
   ops:
@@ -124,9 +124,20 @@ PostCommitPhase stage 5 of 6 with 1 BackfillType op
       BackfilledIndexID: 2
       TableID: 104
       TemporaryIndexID: 3
-PostCommitPhase stage 6 of 6 with 1 ValidationType op
+PostCommitPhase stage 6 of 7 with 3 MutationType ops
+  transitions:
+    [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGED] -> WRITE_ONLY
+  ops:
+    *scop.MakeMergedIndexWriteOnly
+      IndexID: 2
+      TableID: 104
+    *scop.SetJobStateOnDescriptor
+      DescriptorID: 104
+    *scop.UpdateSchemaChangerJob
+      JobID: 1
+PostCommitPhase stage 7 of 7 with 1 ValidationType op
   transitions:
-    [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGED] -> VALIDATED
+    [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], WRITE_ONLY] -> VALIDATED
   ops:
     *scop.ValidateUniqueIndex
       IndexID: 2
@@ -304,14 +315,14 @@ PreCommitPhase stage 1 of 1 with 2 MutationType ops
       DescriptorIDs:
       - 104
       JobID: 1
-      RunningStatus: PostCommitPhase stage 1 of 6 with 1 MutationType op pending
+      RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
       Statements:
       - statement: CREATE INVERTED INDEX CONCURRENTLY id1 ON defaultdb.t1 (id, name) STORING
           (money)
         redactedstatement: CREATE INVERTED INDEX CONCURRENTLY ‹id1› ON ‹defaultdb›.public.‹t1›
           (‹id›, ‹name›) STORING (‹money›)
         statementtag: CREATE INDEX
-PostCommitPhase stage 1 of 6 with 3 MutationType ops
+PostCommitPhase stage 1 of 7 with 3 MutationType ops
   transitions:
     [[TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}, TRANSIENT_ABSENT], DELETE_ONLY] -> WRITE_ONLY
   ops:
@@ -322,7 +333,7 @@ PostCommitPhase stage 1 of 6 with 3 MutationType ops
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 2 of 6 with 1 BackfillType op
+PostCommitPhase stage 2 of 7 with 1 BackfillType op
   transitions:
     [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], BACKFILL_ONLY] -> BACKFILLED
   ops:
@@ -330,7 +341,7 @@ PostCommitPhase stage 2 of 6 with 1 BackfillType op
       IndexID: 2
       SourceIndexID: 1
       TableID: 104
-PostCommitPhase stage 3 of 6 with 3 MutationType ops
+PostCommitPhase stage 3 of 7 with 3 MutationType ops
   transitions:
     [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], BACKFILLED] -> DELETE_ONLY
   ops:
@@ -341,18 +352,18 @@ PostCommitPhase stage 3 of 6 with 3 MutationType ops
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 4 of 6 with 3 MutationType ops
+PostCommitPhase stage 4 of 7 with 3 MutationType ops
   transitions:
     [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], DELETE_ONLY] -> MERGE_ONLY
   ops:
-    *scop.MakeAddedIndexDeleteAndWriteOnly
+    *scop.MakeBackfilledIndexMerging
       IndexID: 2
       TableID: 104
     *scop.SetJobStateOnDescriptor
       DescriptorID: 104
     *scop.UpdateSchemaChangerJob
       JobID: 1
-PostCommitPhase stage 5 of 6 with 1 BackfillType op
+PostCommitPhase stage 5 of 7 with 1 BackfillType op
   transitions:
     [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGE_ONLY] -> MERGED
   ops:
@@ -360,9 +371,20 @@ PostCommitPhase stage 5 of 6 with 1 BackfillType op
       BackfilledIndexID: 2
       TableID: 104
       TemporaryIndexID: 3
-PostCommitPhase stage 6 of 6 with 1 ValidationType op
+PostCommitPhase stage 6 of 7 with 3 MutationType ops
+  transitions:
+    [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGED] -> WRITE_ONLY
+  ops:
+    *scop.MakeMergedIndexWriteOnly
+      IndexID: 2
+      TableID: 104
+    *scop.SetJobStateOnDescriptor
+      DescriptorID: 104
+    *scop.UpdateSchemaChangerJob
+      JobID: 1
+PostCommitPhase stage 7 of 7 with 1 ValidationType op
   transitions:
-    [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], MERGED] -> VALIDATED
+    [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}, PUBLIC], WRITE_ONLY] -> VALIDATED
   ops:
     *scop.ValidateUniqueIndex
       IndexID: 2
diff --git a/pkg/sql/schemachanger/scplan/testdata/drop_index b/pkg/sql/schemachanger/scplan/testdata/drop_index
index da85549005ef..b5eb76d4dbe3 100644
--- a/pkg/sql/schemachanger/scplan/testdata/drop_index
+++ b/pkg/sql/schemachanger/scplan/testdata/drop_index
@@ -305,6 +305,10 @@ DROP INDEX idx2 CASCADE
   to:   [SecondaryIndex:{DescID: 104, IndexID: 4, ConstraintID: 0}, ABSENT]
   kind: Precedence
   rule: dependents removed before index
+- from: [SecondaryIndex:{DescID: 104, IndexID: 4, ConstraintID: 0}, ABSENT]
+  to:   [Column:{DescID: 104, ColumnID: 4}, ABSENT]
+  kind: Precedence
+  rule: indexes containing columns reach absent before column
 - from: [SecondaryIndex:{DescID: 104, IndexID: 4, ConstraintID: 0}, DELETE_ONLY]
   to:   [IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}, ABSENT]
   kind: Precedence
@@ -520,6 +524,10 @@ DROP INDEX idx3 CASCADE
   to:   [SecondaryIndex:{DescID: 104, IndexID: 6, ConstraintID: 0}, ABSENT]
   kind: Precedence
   rule: dependents removed before index
+- from: [SecondaryIndex:{DescID: 104, IndexID: 6, ConstraintID: 0}, ABSENT]
+  to:   [Column:{DescID: 104, ColumnID: 5}, ABSENT]
+  kind: Precedence
+  rule: indexes containing columns reach absent before column
 - from: [SecondaryIndex:{DescID: 104, IndexID: 6, ConstraintID: 0}, DELETE_ONLY]
   to:   [IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 6}, ABSENT]
   kind: Precedence
diff --git a/pkg/sql/schemachanger/testdata/end_to_end/alter_table_add_column b/pkg/sql/schemachanger/testdata/end_to_end/alter_table_add_column
index 56aee6239d44..a752a391828a 100644
--- a/pkg/sql/schemachanger/testdata/end_to_end/alter_table_add_column
+++ b/pkg/sql/schemachanger/testdata/end_to_end/alter_table_add_column
@@ -159,7 +159,7 @@ notified job registry to adopt jobs: [1]
 begin transaction #2
 commit transaction #2
 begin transaction #3
-## PostCommitPhase stage 1 of 6 with 4 MutationType ops
+## PostCommitPhase stage 1 of 7 with 4 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
@@ -188,14 +188,14 @@ upsert descriptor #106
      unexposedParentSchemaId: 105
   -  version: "2"
   +  version: "3"
-update progress of schema change job #1: "PostCommitPhase stage 2 of 6 with 1 BackfillType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 2 of 7 with 1 BackfillType op pending"
 commit transaction #3
 begin transaction #4
-## PostCommitPhase stage 2 of 6 with 1 BackfillType op
+## PostCommitPhase stage 2 of 7 with 1 BackfillType op
 backfill indexes [2] from index #1 in table #106
 commit transaction #4
 begin transaction #5
-## PostCommitPhase stage 3 of 6 with 3 MutationType ops
+## PostCommitPhase stage 3 of 7 with 3 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
@@ -217,10 +217,10 @@ upsert descriptor #106
      unexposedParentSchemaId: 105
   -  version: "3"
   +  version: "4"
-update progress of schema change job #1: "PostCommitPhase stage 4 of 6 with 1 MutationType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 4 of 7 with 1 MutationType op pending"
 commit transaction #5
 begin transaction #6
-## PostCommitPhase stage 4 of 6 with 3 MutationType ops
+## PostCommitPhase stage 4 of 7 with 3 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
@@ -234,7 +234,7 @@ upsert descriptor #106
          version: 4
        mutationId: 1
   -    state: DELETE_ONLY
-  +    state: DELETE_AND_WRITE_ONLY
+  +    state: MERGING
      - direction: ADD
        index:
   ...
@@ -242,17 +242,42 @@ upsert descriptor #106
      unexposedParentSchemaId: 105
   -  version: "4"
   +  version: "5"
-update progress of schema change job #1: "PostCommitPhase stage 5 of 6 with 1 BackfillType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 5 of 7 with 1 BackfillType op pending"
 commit transaction #6
 begin transaction #7
-## PostCommitPhase stage 5 of 6 with 1 BackfillType op
+## PostCommitPhase stage 5 of 7 with 1 BackfillType op
 merge temporary indexes [3] into backfilled indexes [2] in table #106
 commit transaction #7
 begin transaction #8
-## PostCommitPhase stage 6 of 6 with 1 ValidationType op
-validate forward indexes [2] in table #106
+## PostCommitPhase stage 6 of 7 with 3 MutationType ops
+upsert descriptor #106
+  ...
+     formatVersion: 3
+     id: 106
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 105
+  -  version: "5"
+  +  version: "6"
+update progress of schema change job #1: "PostCommitPhase stage 7 of 7 with 1 ValidationType op pending"
 commit transaction #8
 begin transaction #9
+## PostCommitPhase stage 7 of 7 with 1 ValidationType op
+validate forward indexes [2] in table #106
+commit transaction #9
+begin transaction #10
 ## PostCommitNonRevertiblePhase stage 1 of 3 with 10 MutationType ops
 upsert descriptor #106
   ...
@@ -278,7 +303,7 @@ upsert descriptor #106
      formatVersion: 3
      id: 106
   -  modificationTime:
-  -    wallTime: "1640995200000000006"
+  -    wallTime: "1640995200000000008"
   +  modificationTime: {}
      mutations:
   -  - column:
@@ -376,20 +401,20 @@ upsert descriptor #106
   ...
        time: {}
      unexposedParentSchemaId: 105
-  -  version: "5"
-  +  version: "6"
+  -  version: "6"
+  +  version: "7"
 adding table for stats refresh: 106
 update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending"
 set schema change job #1 to non-cancellable
-commit transaction #9
-begin transaction #10
+commit transaction #10
+begin transaction #11
 ## PostCommitNonRevertiblePhase stage 2 of 3 with 3 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
      id: 106
   -  modificationTime:
-  -    wallTime: "1640995200000000009"
+  -    wallTime: "1640995200000000010"
   +  modificationTime: {}
      mutations:
      - direction: DROP
@@ -403,11 +428,11 @@ upsert descriptor #106
   ...
        time: {}
      unexposedParentSchemaId: 105
-  -  version: "6"
-  +  version: "7"
+  -  version: "7"
+  +  version: "8"
 update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 3 of 3 with 4 MutationType ops pending"
-commit transaction #10
-begin transaction #11
+commit transaction #11
+begin transaction #12
 ## PostCommitNonRevertiblePhase stage 3 of 3 with 6 MutationType ops
 upsert descriptor #106
   ...
@@ -432,7 +457,7 @@ upsert descriptor #106
      formatVersion: 3
      id: 106
   -  modificationTime:
-  -    wallTime: "1640995200000000010"
+  -    wallTime: "1640995200000000011"
   -  mutations:
   -  - direction: DROP
   -    index:
@@ -490,12 +515,12 @@ upsert descriptor #106
   ...
        time: {}
      unexposedParentSchemaId: 105
-  -  version: "7"
-  +  version: "8"
+  -  version: "8"
+  +  version: "9"
 write *eventpb.FinishSchemaChange to event log for descriptor 106
 create job #2 (non-cancelable: true): "GC for ALTER TABLE db.public.tbl ADD COLUMN j INT8 NOT NULL DEFAULT 42"
   descriptor IDs: [106]
 update progress of schema change job #1: "all stages completed"
-commit transaction #11
+commit transaction #12
 notified job registry to adopt jobs: [2]
 # end PostCommitPhase
diff --git a/pkg/sql/schemachanger/testdata/end_to_end/alter_table_add_column_default_seq b/pkg/sql/schemachanger/testdata/end_to_end/alter_table_add_column_default_seq
index 1c3da7a1f9d2..be65dce56d8f 100644
--- a/pkg/sql/schemachanger/testdata/end_to_end/alter_table_add_column_default_seq
+++ b/pkg/sql/schemachanger/testdata/end_to_end/alter_table_add_column_default_seq
@@ -204,7 +204,7 @@ notified job registry to adopt jobs: [1]
 begin transaction #2
 commit transaction #2
 begin transaction #3
-## PostCommitPhase stage 1 of 6 with 5 MutationType ops
+## PostCommitPhase stage 1 of 7 with 5 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
@@ -247,14 +247,14 @@ upsert descriptor #107
      unexposedParentSchemaId: 105
   -  version: "2"
   +  version: "3"
-update progress of schema change job #1: "PostCommitPhase stage 2 of 6 with 1 BackfillType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 2 of 7 with 1 BackfillType op pending"
 commit transaction #3
 begin transaction #4
-## PostCommitPhase stage 2 of 6 with 1 BackfillType op
+## PostCommitPhase stage 2 of 7 with 1 BackfillType op
 backfill indexes [2] from index #1 in table #106
 commit transaction #4
 begin transaction #5
-## PostCommitPhase stage 3 of 6 with 4 MutationType ops
+## PostCommitPhase stage 3 of 7 with 4 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
@@ -290,10 +290,10 @@ upsert descriptor #107
      unexposedParentSchemaId: 105
   -  version: "3"
   +  version: "4"
-update progress of schema change job #1: "PostCommitPhase stage 4 of 6 with 1 MutationType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 4 of 7 with 1 MutationType op pending"
 commit transaction #5
 begin transaction #6
-## PostCommitPhase stage 4 of 6 with 4 MutationType ops
+## PostCommitPhase stage 4 of 7 with 4 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
@@ -307,7 +307,7 @@ upsert descriptor #106
          version: 4
        mutationId: 1
   -    state: DELETE_ONLY
-  +    state: DELETE_AND_WRITE_ONLY
+  +    state: MERGING
      - direction: ADD
        index:
   ...
@@ -329,17 +329,56 @@ upsert descriptor #107
      unexposedParentSchemaId: 105
   -  version: "4"
   +  version: "5"
-update progress of schema change job #1: "PostCommitPhase stage 5 of 6 with 1 BackfillType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 5 of 7 with 1 BackfillType op pending"
 commit transaction #6
 begin transaction #7
-## PostCommitPhase stage 5 of 6 with 1 BackfillType op
+## PostCommitPhase stage 5 of 7 with 1 BackfillType op
 merge temporary indexes [3] into backfilled indexes [2] in table #106
 commit transaction #7
 begin transaction #8
-## PostCommitPhase stage 6 of 6 with 1 ValidationType op
-validate forward indexes [2] in table #106
+## PostCommitPhase stage 6 of 7 with 4 MutationType ops
+upsert descriptor #106
+  ...
+     formatVersion: 3
+     id: 106
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 105
+  -  version: "5"
+  +  version: "6"
+upsert descriptor #107
+  ...
+     formatVersion: 3
+     id: 107
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     name: sq1
+     parentId: 104
+  ...
+       start: "1"
+     unexposedParentSchemaId: 105
+  -  version: "5"
+  +  version: "6"
+update progress of schema change job #1: "PostCommitPhase stage 7 of 7 with 1 ValidationType op pending"
 commit transaction #8
 begin transaction #9
+## PostCommitPhase stage 7 of 7 with 1 ValidationType op
+validate forward indexes [2] in table #106
+commit transaction #9
+begin transaction #10
 ## PostCommitNonRevertiblePhase stage 1 of 3 with 11 MutationType ops
 upsert descriptor #106
   ...
@@ -367,7 +406,7 @@ upsert descriptor #106
      formatVersion: 3
      id: 106
   -  modificationTime:
-  -    wallTime: "1640995200000000006"
+  -    wallTime: "1640995200000000008"
   +  modificationTime: {}
      mutations:
   -  - column:
@@ -467,8 +506,8 @@ upsert descriptor #106
   ...
        time: {}
      unexposedParentSchemaId: 105
-  -  version: "5"
-  +  version: "6"
+  -  version: "6"
+  +  version: "7"
 upsert descriptor #107
   ...
          userName: root
@@ -480,27 +519,27 @@ upsert descriptor #107
      formatVersion: 3
      id: 107
   -  modificationTime:
-  -    wallTime: "1640995200000000006"
+  -    wallTime: "1640995200000000008"
   +  modificationTime: {}
      name: sq1
      parentId: 104
   ...
        start: "1"
      unexposedParentSchemaId: 105
-  -  version: "5"
-  +  version: "6"
+  -  version: "6"
+  +  version: "7"
 adding table for stats refresh: 106
 update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending"
 set schema change job #1 to non-cancellable
-commit transaction #9
-begin transaction #10
+commit transaction #10
+begin transaction #11
 ## PostCommitNonRevertiblePhase stage 2 of 3 with 4 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
      id: 106
   -  modificationTime:
-  -    wallTime: "1640995200000000009"
+  -    wallTime: "1640995200000000010"
   +  modificationTime: {}
      mutations:
      - direction: DROP
@@ -514,25 +553,25 @@ upsert descriptor #106
   ...
        time: {}
      unexposedParentSchemaId: 105
-  -  version: "6"
-  +  version: "7"
+  -  version: "7"
+  +  version: "8"
 upsert descriptor #107
   ...
      formatVersion: 3
      id: 107
   -  modificationTime:
-  -    wallTime: "1640995200000000009"
+  -    wallTime: "1640995200000000010"
   +  modificationTime: {}
      name: sq1
      parentId: 104
   ...
        start: "1"
      unexposedParentSchemaId: 105
-  -  version: "6"
-  +  version: "7"
+  -  version: "7"
+  +  version: "8"
 update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 3 of 3 with 4 MutationType ops pending"
-commit transaction #10
-begin transaction #11
+commit transaction #11
+begin transaction #12
 ## PostCommitNonRevertiblePhase stage 3 of 3 with 7 MutationType ops
 upsert descriptor #106
   ...
@@ -557,7 +596,7 @@ upsert descriptor #106
      formatVersion: 3
      id: 106
   -  modificationTime:
-  -    wallTime: "1640995200000000010"
+  -    wallTime: "1640995200000000011"
   -  mutations:
   -  - direction: DROP
   -    index:
@@ -615,8 +654,8 @@ upsert descriptor #106
   ...
        time: {}
      unexposedParentSchemaId: 105
-  -  version: "7"
-  +  version: "8"
+  -  version: "8"
+  +  version: "9"
 upsert descriptor #107
   ...
      createAsOfTime:
@@ -631,19 +670,19 @@ upsert descriptor #107
      formatVersion: 3
      id: 107
   -  modificationTime:
-  -    wallTime: "1640995200000000010"
+  -    wallTime: "1640995200000000011"
   +  modificationTime: {}
      name: sq1
      parentId: 104
   ...
        start: "1"
      unexposedParentSchemaId: 105
-  -  version: "7"
-  +  version: "8"
+  -  version: "8"
+  +  version: "9"
 write *eventpb.FinishSchemaChange to event log for descriptor 106
 create job #2 (non-cancelable: true): "GC for ALTER TABLE db.public.tbl ADD COLUMN l INT8 NOT NULL DEFAULT nextval('db.public.sq1')"
   descriptor IDs: [106]
 update progress of schema change job #1: "all stages completed"
-commit transaction #11
+commit transaction #12
 notified job registry to adopt jobs: [2]
 # end PostCommitPhase
diff --git a/pkg/sql/schemachanger/testdata/end_to_end/create_index b/pkg/sql/schemachanger/testdata/end_to_end/create_index
index 752f1b555570..61acae4dc70e 100644
--- a/pkg/sql/schemachanger/testdata/end_to_end/create_index
+++ b/pkg/sql/schemachanger/testdata/end_to_end/create_index
@@ -124,7 +124,7 @@ notified job registry to adopt jobs: [1]
 begin transaction #2
 commit transaction #2
 begin transaction #3
-## PostCommitPhase stage 1 of 6 with 3 MutationType ops
+## PostCommitPhase stage 1 of 7 with 3 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
@@ -146,14 +146,14 @@ upsert descriptor #106
      unexposedParentSchemaId: 101
   -  version: "2"
   +  version: "3"
-update progress of schema change job #1: "PostCommitPhase stage 2 of 6 with 1 BackfillType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 2 of 7 with 1 BackfillType op pending"
 commit transaction #3
 begin transaction #4
-## PostCommitPhase stage 2 of 6 with 1 BackfillType op
+## PostCommitPhase stage 2 of 7 with 1 BackfillType op
 backfill indexes [2] from index #1 in table #106
 commit transaction #4
 begin transaction #5
-## PostCommitPhase stage 3 of 6 with 3 MutationType ops
+## PostCommitPhase stage 3 of 7 with 3 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
@@ -175,10 +175,10 @@ upsert descriptor #106
      unexposedParentSchemaId: 101
   -  version: "3"
   +  version: "4"
-update progress of schema change job #1: "PostCommitPhase stage 4 of 6 with 1 MutationType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 4 of 7 with 1 MutationType op pending"
 commit transaction #5
 begin transaction #6
-## PostCommitPhase stage 4 of 6 with 3 MutationType ops
+## PostCommitPhase stage 4 of 7 with 3 MutationType ops
 upsert descriptor #106
   ...
      formatVersion: 3
@@ -192,7 +192,7 @@ upsert descriptor #106
          version: 4
        mutationId: 1
   -    state: DELETE_ONLY
-  +    state: DELETE_AND_WRITE_ONLY
+  +    state: MERGING
      - direction: ADD
        index:
   ...
@@ -200,17 +200,42 @@ upsert descriptor #106
      unexposedParentSchemaId: 101
   -  version: "4"
   +  version: "5"
-update progress of schema change job #1: "PostCommitPhase stage 5 of 6 with 1 BackfillType op pending"
+update progress of schema change job #1: "PostCommitPhase stage 5 of 7 with 1 BackfillType op pending"
 commit transaction #6
 begin transaction #7
-## PostCommitPhase stage 5 of 6 with 1 BackfillType op
+## PostCommitPhase stage 5 of 7 with 1 BackfillType op
 merge temporary indexes [3] into backfilled indexes [2] in table #106
 commit transaction #7
 begin transaction #8
-## PostCommitPhase stage 6 of 6 with 1 ValidationType op
-validate forward indexes [2] in table #106
+## PostCommitPhase stage 6 of 7 with 3 MutationType ops
+upsert descriptor #106
+  ...
+     formatVersion: 3
+     id: 106
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     mutations:
+     - direction: ADD
+  ...
+         version: 4
+       mutationId: 1
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "5"
+  +  version: "6"
+update progress of schema change job #1: "PostCommitPhase stage 7 of 7 with 1 ValidationType op pending"
 commit transaction #8
 begin transaction #9
+## PostCommitPhase stage 7 of 7 with 1 ValidationType op
+validate forward indexes [2] in table #106
+commit transaction #9
+begin transaction #10
 ## PostCommitNonRevertiblePhase stage 1 of 2 with 5 MutationType ops
 upsert descriptor #106
   ...
@@ -223,7 +248,7 @@ upsert descriptor #106
      formatVersion: 3
      id: 106
   -  modificationTime:
-  -    wallTime: "1640995200000000006"
+  -    wallTime: "1640995200000000008"
   +  indexes:
   +  - constraintId: 2
   +    createdExplicitly: true
@@ -284,12 +309,12 @@ upsert descriptor #106
   ...
        time: {}
      unexposedParentSchemaId: 101
-  -  version: "5"
-  +  version: "6"
+  -  version: "6"
+  +  version: "7"
 update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 2 of 2 with 2 MutationType ops pending"
 set schema change job #1 to non-cancellable
-commit transaction #9
-begin transaction #10
+commit transaction #10
+begin transaction #11
 ## PostCommitNonRevertiblePhase stage 2 of 2 with 4 MutationType ops
 upsert descriptor #106
   ...
@@ -314,7 +339,7 @@ upsert descriptor #106
        storeColumnNames: []
        version: 4
   -  modificationTime:
-  -    wallTime: "1640995200000000009"
+  -    wallTime: "1640995200000000010"
   -  mutations:
   -  - direction: DROP
   -    index:
@@ -347,12 +372,12 @@ upsert descriptor #106
   ...
        time: {}
      unexposedParentSchemaId: 101
-  -  version: "6"
-  +  version: "7"
+  -  version: "7"
+  +  version: "8"
 write *eventpb.FinishSchemaChange to event log for descriptor 106
 create job #2 (non-cancelable: true): "GC for "
   descriptor IDs: [106]
 update progress of schema change job #1: "all stages completed"
-commit transaction #10
+commit transaction #11
 notified job registry to adopt jobs: [2]
 # end PostCommitPhase
diff --git a/pkg/sql/schemachanger/testdata/explain/alter_table_add_column b/pkg/sql/schemachanger/testdata/explain/alter_table_add_column
index 0cbbba914b63..eee6a8f4f7fc 100644
--- a/pkg/sql/schemachanger/testdata/explain/alter_table_add_column
+++ b/pkg/sql/schemachanger/testdata/explain/alter_table_add_column
@@ -39,7 +39,7 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
  │              ├── SetJobStateOnDescriptor {"DescriptorID":106,"Initialize":true}
  │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
  ├── PostCommitPhase
- │    ├── Stage 1 of 6 in PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── DELETE_ONLY → WRITE_ONLY Column:{DescID: 106, ColumnID: 2}
  │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
@@ -49,33 +49,40 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
  │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":3,"TableID":106}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 2 of 6 in PostCommitPhase
+ │    ├── Stage 2 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── BACKFILL_ONLY → BACKFILLED PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 1 Backfill operation
  │    │         └── BackfillIndex {"IndexID":2,"SourceIndexID":1,"TableID":106}
- │    ├── Stage 3 of 6 in PostCommitPhase
+ │    ├── Stage 3 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── BACKFILLED → DELETE_ONLY PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 3 Mutation operations
  │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":2,"TableID":106}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 4 of 6 in PostCommitPhase
+ │    ├── Stage 4 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── DELETE_ONLY → MERGE_ONLY PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 3 Mutation operations
- │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":2,"TableID":106}
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":2,"TableID":106}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 5 of 6 in PostCommitPhase
+ │    ├── Stage 5 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── MERGE_ONLY → MERGED PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 1 Backfill operation
  │    │         └── MergeIndex {"BackfilledIndexID":2,"TableID":106,"TemporaryIndexID":3}
- │    └── Stage 6 of 6 in PostCommitPhase
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":2,"TableID":106}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
  │         ├── 1 element transitioning toward PUBLIC
- │         │    └── MERGED → VALIDATED PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │         │    └── WRITE_ONLY → VALIDATED PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
  │         └── 1 Validation operation
  │              └── ValidateUniqueIndex {"IndexID":2,"TableID":106}
  └── PostCommitNonRevertiblePhase
diff --git a/pkg/sql/schemachanger/testdata/explain/alter_table_add_column_default_seq b/pkg/sql/schemachanger/testdata/explain/alter_table_add_column_default_seq
index d2871ec85822..b701889d88b6 100644
--- a/pkg/sql/schemachanger/testdata/explain/alter_table_add_column_default_seq
+++ b/pkg/sql/schemachanger/testdata/explain/alter_table_add_column_default_seq
@@ -41,7 +41,7 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
  │              ├── SetJobStateOnDescriptor {"DescriptorID":107,"Initialize":true}
  │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
  ├── PostCommitPhase
- │    ├── Stage 1 of 6 in PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── DELETE_ONLY → WRITE_ONLY Column:{DescID: 106, ColumnID: 2}
  │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
@@ -52,12 +52,12 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":107}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 2 of 6 in PostCommitPhase
+ │    ├── Stage 2 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── BACKFILL_ONLY → BACKFILLED PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 1 Backfill operation
  │    │         └── BackfillIndex {"IndexID":2,"SourceIndexID":1,"TableID":106}
- │    ├── Stage 3 of 6 in PostCommitPhase
+ │    ├── Stage 3 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── BACKFILLED → DELETE_ONLY PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 4 Mutation operations
@@ -65,22 +65,30 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":107}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 4 of 6 in PostCommitPhase
+ │    ├── Stage 4 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── DELETE_ONLY → MERGE_ONLY PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 4 Mutation operations
- │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":2,"TableID":106}
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":2,"TableID":106}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":107}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 5 of 6 in PostCommitPhase
+ │    ├── Stage 5 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── MERGE_ONLY → MERGED PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 1 Backfill operation
  │    │         └── MergeIndex {"BackfilledIndexID":2,"TableID":106,"TemporaryIndexID":3}
- │    └── Stage 6 of 6 in PostCommitPhase
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │    │    └── 4 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":2,"TableID":106}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":107}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
  │         ├── 1 element transitioning toward PUBLIC
- │         │    └── MERGED → VALIDATED PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │         │    └── WRITE_ONLY → VALIDATED PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
  │         └── 1 Validation operation
  │              └── ValidateUniqueIndex {"IndexID":2,"TableID":106}
  └── PostCommitNonRevertiblePhase
diff --git a/pkg/sql/schemachanger/testdata/explain/create_index b/pkg/sql/schemachanger/testdata/explain/create_index
index 274fbce7a8e4..f23b8ce317e0 100644
--- a/pkg/sql/schemachanger/testdata/explain/create_index
+++ b/pkg/sql/schemachanger/testdata/explain/create_index
@@ -29,40 +29,47 @@ Schema change plan for CREATE INDEX ‹idx1› ON ‹defaultdb›.‹public›.
  │              ├── SetJobStateOnDescriptor {"DescriptorID":106,"Initialize":true}
  │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
  ├── PostCommitPhase
- │    ├── Stage 1 of 6 in PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
  │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 106, IndexID: 3, SourceIndexID: 1}
  │    │    └── 3 Mutation operations
  │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":3,"TableID":106}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 2 of 6 in PostCommitPhase
+ │    ├── Stage 2 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── BACKFILL_ONLY → BACKFILLED SecondaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 1 Backfill operation
  │    │         └── BackfillIndex {"IndexID":2,"SourceIndexID":1,"TableID":106}
- │    ├── Stage 3 of 6 in PostCommitPhase
+ │    ├── Stage 3 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── BACKFILLED → DELETE_ONLY SecondaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 3 Mutation operations
  │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":2,"TableID":106}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 4 of 6 in PostCommitPhase
+ │    ├── Stage 4 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── DELETE_ONLY → MERGE_ONLY SecondaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 3 Mutation operations
- │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":2,"TableID":106}
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":2,"TableID":106}
  │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
  │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
- │    ├── Stage 5 of 6 in PostCommitPhase
+ │    ├── Stage 5 of 7 in PostCommitPhase
  │    │    ├── 1 element transitioning toward PUBLIC
  │    │    │    └── MERGE_ONLY → MERGED SecondaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    └── 1 Backfill operation
  │    │         └── MergeIndex {"BackfilledIndexID":2,"TableID":106,"TemporaryIndexID":3}
- │    └── Stage 6 of 6 in PostCommitPhase
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY SecondaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":2,"TableID":106}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
  │         ├── 1 element transitioning toward PUBLIC
- │         │    └── MERGED → VALIDATED SecondaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
+ │         │    └── WRITE_ONLY → VALIDATED SecondaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
  │         └── 1 Validation operation
  │              └── ValidateUniqueIndex {"IndexID":2,"TableID":106}
  └── PostCommitNonRevertiblePhase
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/alter_table_add_column b/pkg/sql/schemachanger/testdata/explain_verbose/alter_table_add_column
index 56dc6121368c..00f78837c243 100644
--- a/pkg/sql/schemachanger/testdata/explain_verbose/alter_table_add_column
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/alter_table_add_column
@@ -196,7 +196,7 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN j INT NOT NULL DEFAU
 │                 DescriptorIDs:
 │                 - 106
 │                 JobID: 1
-│                 RunningStatus: PostCommitPhase stage 1 of 6 with 2 MutationType ops pending
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 2 MutationType ops pending
 │                 Statements:
 │                 - statement: ALTER TABLE db.public.tbl ADD COLUMN j INT8 NOT NULL DEFAULT 42
 │                   redactedstatement: ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN ‹j› INT8 NOT NULL
@@ -205,7 +205,7 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN j INT NOT NULL DEFAU
 │
 ├── • PostCommitPhase
 │   │
-│   ├── • Stage 1 of 6 in PostCommitPhase
+│   ├── • Stage 1 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -220,6 +220,9 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN j INT NOT NULL DEFAU
 │   │   │   └── • TemporaryIndex:{DescID: 106, IndexID: 3, SourceIndexID: 1}
 │   │   │       │ DELETE_ONLY → WRITE_ONLY
 │   │   │       │
+│   │   │       ├── • Precedence dependency from WRITE_ONLY Column:{DescID: 106, ColumnID: 2}
+│   │   │       │     rule: "column is WRITE_ONLY before temporary index is WRITE_ONLY"
+│   │   │       │
 │   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 3}
 │   │   │       │     rule: "index-column added to index before temp index receives writes"
 │   │   │       │
@@ -241,9 +244,9 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN j INT NOT NULL DEFAU
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 2 of 6 with 1 BackfillType op pending
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
 │   │
-│   ├── • Stage 2 of 6 in PostCommitPhase
+│   ├── • Stage 2 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -266,7 +269,7 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN j INT NOT NULL DEFAU
 │   │             SourceIndexID: 1
 │   │             TableID: 106
 │   │
-│   ├── • Stage 3 of 6 in PostCommitPhase
+│   ├── • Stage 3 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -284,9 +287,9 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN j INT NOT NULL DEFAU
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 4 of 6 with 1 MutationType op pending
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
 │   │
-│   ├── • Stage 4 of 6 in PostCommitPhase
+│   ├── • Stage 4 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -295,7 +298,7 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN j INT NOT NULL DEFAU
 │   │   │
 │   │   └── • 3 Mutation operations
 │   │       │
-│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       ├── • MakeBackfilledIndexMerging
 │   │       │     IndexID: 2
 │   │       │     TableID: 106
 │   │       │
@@ -304,9 +307,9 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN j INT NOT NULL DEFAU
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 5 of 6 with 1 BackfillType op pending
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
 │   │
-│   ├── • Stage 5 of 6 in PostCommitPhase
+│   ├── • Stage 5 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -320,12 +323,32 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN j INT NOT NULL DEFAU
 │   │             TableID: 106
 │   │             TemporaryIndexID: 3
 │   │
-│   └── • Stage 6 of 6 in PostCommitPhase
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 2
+│   │       │     TableID: 106
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 106
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
 │       │
 │       ├── • 1 element transitioning toward PUBLIC
 │       │   │
 │       │   └── • PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
-│       │         MERGED → VALIDATED
+│       │         WRITE_ONLY → VALIDATED
 │       │
 │       └── • 1 Validation operation
 │           │
@@ -360,7 +383,7 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN j INT NOT NULL DEFAU
     │   │   │   │ WRITE_ONLY → PUBLIC
     │   │   │   │
     │   │   │   └── • Precedence dependency from PUBLIC PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
-    │   │   │         rule: "column depends on primary index"
+    │   │   │         rule: "adding column depends on primary index"
     │   │   │
     │   │   ├── • PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
     │   │   │   │ VALIDATED → PUBLIC
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/alter_table_add_column_default_seq b/pkg/sql/schemachanger/testdata/explain_verbose/alter_table_add_column_default_seq
index df8b2343a128..6512f3a330f5 100644
--- a/pkg/sql/schemachanger/testdata/explain_verbose/alter_table_add_column_default_seq
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/alter_table_add_column_default_seq
@@ -209,7 +209,7 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN l INT NOT NULL DEFAU
 │                 - 106
 │                 - 107
 │                 JobID: 1
-│                 RunningStatus: PostCommitPhase stage 1 of 6 with 2 MutationType ops pending
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 2 MutationType ops pending
 │                 Statements:
 │                 - statement: ALTER TABLE db.public.tbl ADD COLUMN l INT8 NOT NULL DEFAULT nextval('db.public.sq1')
 │                   redactedstatement: ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN ‹l› INT8 NOT NULL
@@ -218,7 +218,7 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN l INT NOT NULL DEFAU
 │
 ├── • PostCommitPhase
 │   │
-│   ├── • Stage 1 of 6 in PostCommitPhase
+│   ├── • Stage 1 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -233,6 +233,9 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN l INT NOT NULL DEFAU
 │   │   │   └── • TemporaryIndex:{DescID: 106, IndexID: 3, SourceIndexID: 1}
 │   │   │       │ DELETE_ONLY → WRITE_ONLY
 │   │   │       │
+│   │   │       ├── • Precedence dependency from WRITE_ONLY Column:{DescID: 106, ColumnID: 2}
+│   │   │       │     rule: "column is WRITE_ONLY before temporary index is WRITE_ONLY"
+│   │   │       │
 │   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 3}
 │   │   │       │     rule: "index-column added to index before temp index receives writes"
 │   │   │       │
@@ -257,9 +260,9 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN l INT NOT NULL DEFAU
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 2 of 6 with 1 BackfillType op pending
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
 │   │
-│   ├── • Stage 2 of 6 in PostCommitPhase
+│   ├── • Stage 2 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -282,7 +285,7 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN l INT NOT NULL DEFAU
 │   │             SourceIndexID: 1
 │   │             TableID: 106
 │   │
-│   ├── • Stage 3 of 6 in PostCommitPhase
+│   ├── • Stage 3 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -303,9 +306,9 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN l INT NOT NULL DEFAU
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 4 of 6 with 1 MutationType op pending
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
 │   │
-│   ├── • Stage 4 of 6 in PostCommitPhase
+│   ├── • Stage 4 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -314,7 +317,7 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN l INT NOT NULL DEFAU
 │   │   │
 │   │   └── • 4 Mutation operations
 │   │       │
-│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       ├── • MakeBackfilledIndexMerging
 │   │       │     IndexID: 2
 │   │       │     TableID: 106
 │   │       │
@@ -326,9 +329,9 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN l INT NOT NULL DEFAU
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 5 of 6 with 1 BackfillType op pending
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
 │   │
-│   ├── • Stage 5 of 6 in PostCommitPhase
+│   ├── • Stage 5 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -342,12 +345,35 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN l INT NOT NULL DEFAU
 │   │             TableID: 106
 │   │             TemporaryIndexID: 3
 │   │
-│   └── • Stage 6 of 6 in PostCommitPhase
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 4 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 2
+│   │       │     TableID: 106
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 106
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 107
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
 │       │
 │       ├── • 1 element transitioning toward PUBLIC
 │       │   │
 │       │   └── • PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
-│       │         MERGED → VALIDATED
+│       │         WRITE_ONLY → VALIDATED
 │       │
 │       └── • 1 Validation operation
 │           │
@@ -382,7 +408,7 @@ EXPLAIN (ddl, verbose) ALTER TABLE db.public.tbl ADD COLUMN l INT NOT NULL DEFAU
     │   │   │   │ WRITE_ONLY → PUBLIC
     │   │   │   │
     │   │   │   └── • Precedence dependency from PUBLIC PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
-    │   │   │         rule: "column depends on primary index"
+    │   │   │         rule: "adding column depends on primary index"
     │   │   │
     │   │   ├── • PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
     │   │   │   │ VALIDATED → PUBLIC
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/create_index b/pkg/sql/schemachanger/testdata/explain_verbose/create_index
index 6a61474749be..e3120fe384e6 100644
--- a/pkg/sql/schemachanger/testdata/explain_verbose/create_index
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/create_index
@@ -102,7 +102,7 @@ EXPLAIN (ddl, verbose) CREATE INDEX idx1 ON t (v) WHERE (v = 'a');
 │                 DescriptorIDs:
 │                 - 106
 │                 JobID: 1
-│                 RunningStatus: PostCommitPhase stage 1 of 6 with 1 MutationType op pending
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
 │                 Statements:
 │                 - statement: CREATE INDEX idx1 ON t (v) WHERE (v = 'a')
 │                   redactedstatement: CREATE INDEX ‹idx1› ON ‹defaultdb›.‹public›.‹t› (‹v›) WHERE (‹v›
@@ -111,7 +111,7 @@ EXPLAIN (ddl, verbose) CREATE INDEX idx1 ON t (v) WHERE (v = 'a');
 │
 ├── • PostCommitPhase
 │   │
-│   ├── • Stage 1 of 6 in PostCommitPhase
+│   ├── • Stage 1 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
 │   │   │   │
@@ -135,9 +135,9 @@ EXPLAIN (ddl, verbose) CREATE INDEX idx1 ON t (v) WHERE (v = 'a');
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 2 of 6 with 1 BackfillType op pending
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
 │   │
-│   ├── • Stage 2 of 6 in PostCommitPhase
+│   ├── • Stage 2 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -160,7 +160,7 @@ EXPLAIN (ddl, verbose) CREATE INDEX idx1 ON t (v) WHERE (v = 'a');
 │   │             SourceIndexID: 1
 │   │             TableID: 106
 │   │
-│   ├── • Stage 3 of 6 in PostCommitPhase
+│   ├── • Stage 3 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -178,9 +178,9 @@ EXPLAIN (ddl, verbose) CREATE INDEX idx1 ON t (v) WHERE (v = 'a');
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 4 of 6 with 1 MutationType op pending
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
 │   │
-│   ├── • Stage 4 of 6 in PostCommitPhase
+│   ├── • Stage 4 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -189,7 +189,7 @@ EXPLAIN (ddl, verbose) CREATE INDEX idx1 ON t (v) WHERE (v = 'a');
 │   │   │
 │   │   └── • 3 Mutation operations
 │   │       │
-│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       ├── • MakeBackfilledIndexMerging
 │   │       │     IndexID: 2
 │   │       │     TableID: 106
 │   │       │
@@ -198,9 +198,9 @@ EXPLAIN (ddl, verbose) CREATE INDEX idx1 ON t (v) WHERE (v = 'a');
 │   │       │
 │   │       └── • UpdateSchemaChangerJob
 │   │             JobID: 1
-│   │             RunningStatus: PostCommitPhase stage 5 of 6 with 1 BackfillType op pending
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
 │   │
-│   ├── • Stage 5 of 6 in PostCommitPhase
+│   ├── • Stage 5 of 7 in PostCommitPhase
 │   │   │
 │   │   ├── • 1 element transitioning toward PUBLIC
 │   │   │   │
@@ -214,12 +214,32 @@ EXPLAIN (ddl, verbose) CREATE INDEX idx1 ON t (v) WHERE (v = 'a');
 │   │             TableID: 106
 │   │             TemporaryIndexID: 3
 │   │
-│   └── • Stage 6 of 6 in PostCommitPhase
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • SecondaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 2
+│   │       │     TableID: 106
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 106
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
 │       │
 │       ├── • 1 element transitioning toward PUBLIC
 │       │   │
 │       │   └── • SecondaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 0, TemporaryIndexID: 3, SourceIndexID: 1}
-│       │         MERGED → VALIDATED
+│       │         WRITE_ONLY → VALIDATED
 │       │
 │       └── • 1 Validation operation
 │           │
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/drop_index_hash_sharded_index b/pkg/sql/schemachanger/testdata/explain_verbose/drop_index_hash_sharded_index
index dd8bea84ac89..5b534801757b 100644
--- a/pkg/sql/schemachanger/testdata/explain_verbose/drop_index_hash_sharded_index
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/drop_index_hash_sharded_index
@@ -188,9 +188,12 @@ EXPLAIN (ddl, verbose) DROP INDEX idx CASCADE;
         │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: crdb_internal_j_shard_16, ColumnID: 3}
         │   │   │     rule: "dependents removed before column"
         │   │   │
-        │   │   └── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
-        │   │         rule: "dependents removed before column"
-        │   │         rule: "column type removed right before column when not dropping relation"
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │   │         rule: "indexes containing columns reach absent before column"
         │   │
         │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
         │   │   │ PUBLIC → ABSENT
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/drop_index_partial_expression_index b/pkg/sql/schemachanger/testdata/explain_verbose/drop_index_partial_expression_index
index 6f7cd1f519d5..a758463eaff7 100644
--- a/pkg/sql/schemachanger/testdata/explain_verbose/drop_index_partial_expression_index
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/drop_index_partial_expression_index
@@ -160,9 +160,12 @@ EXPLAIN (ddl, verbose) DROP INDEX idx CASCADE;
         │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 3}
         │   │   │     rule: "dependents removed before column"
         │   │   │
-        │   │   └── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
-        │   │         rule: "dependents removed before column"
-        │   │         rule: "column type removed right before column when not dropping relation"
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │   │         rule: "indexes containing columns reach absent before column"
         │   │
         │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
         │   │   │ PUBLIC → ABSENT

From b20acd808bc00d45f4610393aa9d58af7daafe54 Mon Sep 17 00:00:00 2001
From: Andrew Werner <awerner32@gmail.com>
Date: Mon, 18 Jul 2022 19:08:32 -0400
Subject: [PATCH 3/6] sql,sqlerrors: extract some errors for reuse

Release note: None
---
 pkg/sql/alter_table.go                        |  3 +-
 pkg/sql/catalog/schemaexpr/BUILD.bazel        |  1 +
 pkg/sql/catalog/schemaexpr/computed_column.go |  8 +---
 pkg/sql/drop_table.go                         |  6 +--
 pkg/sql/sqlerrors/errors.go                   | 39 +++++++++++++++++++
 5 files changed, 45 insertions(+), 12 deletions(-)

diff --git a/pkg/sql/alter_table.go b/pkg/sql/alter_table.go
index c9356bf8922b..55b33720361b 100644
--- a/pkg/sql/alter_table.go
+++ b/pkg/sql/alter_table.go
@@ -1631,8 +1631,7 @@ func dropColumnImpl(
 	}
 
 	if tableDesc.GetPrimaryIndex().CollectKeyColumnIDs().Contains(colToDrop.GetID()) {
-		return nil, pgerror.Newf(pgcode.InvalidColumnReference,
-			"column %q is referenced by the primary key", colToDrop.GetName())
+		return nil, sqlerrors.NewColumnReferencedByPrimaryKeyError(colToDrop.GetName())
 	}
 	var idxNamesToDelete []string
 	for _, idx := range tableDesc.NonDropIndexes() {
diff --git a/pkg/sql/catalog/schemaexpr/BUILD.bazel b/pkg/sql/catalog/schemaexpr/BUILD.bazel
index 9009c5d6a930..f4203fd6424e 100644
--- a/pkg/sql/catalog/schemaexpr/BUILD.bazel
+++ b/pkg/sql/catalog/schemaexpr/BUILD.bazel
@@ -35,6 +35,7 @@ go_library(
         "//pkg/sql/sem/tree/treebin",
         "//pkg/sql/sem/volatility",
         "//pkg/sql/sessiondata",
+        "//pkg/sql/sqlerrors",
         "//pkg/sql/types",
         "//pkg/util/errorutil/unimplemented",
         "@com_github_cockroachdb_errors//:errors",
diff --git a/pkg/sql/catalog/schemaexpr/computed_column.go b/pkg/sql/catalog/schemaexpr/computed_column.go
index 85cde994608a..70ecccef73db 100644
--- a/pkg/sql/catalog/schemaexpr/computed_column.go
+++ b/pkg/sql/catalog/schemaexpr/computed_column.go
@@ -24,6 +24,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/transform"
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/volatility"
+	"github.com/cockroachdb/cockroach/pkg/sql/sqlerrors"
 	"github.com/cockroachdb/cockroach/pkg/sql/types"
 	"github.com/cockroachdb/cockroach/pkg/util/errorutil/unimplemented"
 	"github.com/cockroachdb/errors"
@@ -166,12 +167,7 @@ func ValidateColumnHasNoDependents(desc catalog.TableDescriptor, col catalog.Col
 
 		err = iterColDescriptors(desc, expr, func(colVar catalog.Column) error {
 			if colVar.GetID() == col.GetID() {
-				return pgerror.Newf(
-					pgcode.InvalidColumnReference,
-					"column %q is referenced by computed column %q",
-					col.GetName(),
-					c.GetName(),
-				)
+				return sqlerrors.NewColumnReferencedByComputedColumnError(col.GetName(), c.GetName())
 			}
 			return nil
 		})
diff --git a/pkg/sql/drop_table.go b/pkg/sql/drop_table.go
index 431f8df3c09e..6a853d514287 100644
--- a/pkg/sql/drop_table.go
+++ b/pkg/sql/drop_table.go
@@ -21,11 +21,10 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/tabledesc"
 	"github.com/cockroachdb/cockroach/pkg/sql/descmetadata"
-	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgcode"
-	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgerror"
 	"github.com/cockroachdb/cockroach/pkg/sql/privilege"
 	"github.com/cockroachdb/cockroach/pkg/sql/schemachanger/scerrors"
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
+	"github.com/cockroachdb/cockroach/pkg/sql/sqlerrors"
 	"github.com/cockroachdb/cockroach/pkg/sql/sqltelemetry"
 	"github.com/cockroachdb/cockroach/pkg/util/log"
 	"github.com/cockroachdb/cockroach/pkg/util/log/eventpb"
@@ -209,8 +208,7 @@ func (p *planner) canRemoveFKBackreference(
 		return err
 	}
 	if behavior != tree.DropCascade {
-		return pgerror.Newf(pgcode.DependentObjectsStillExist,
-			"%q is referenced by foreign key from table %q", from, table.Name)
+		return sqlerrors.NewUniqueConstraintReferencedByForeignKeyError(from, table.GetName())
 	}
 	// Check to see whether we're allowed to edit the table that has a
 	// foreign key constraint on the table that we're dropping right now.
diff --git a/pkg/sql/sqlerrors/errors.go b/pkg/sql/sqlerrors/errors.go
index 97ee2aaba406..33bd6ee32bb5 100644
--- a/pkg/sql/sqlerrors/errors.go
+++ b/pkg/sql/sqlerrors/errors.go
@@ -237,6 +237,45 @@ func NewDependentObjectErrorf(format string, args ...interface{}) error {
 	return pgerror.Newf(pgcode.DependentObjectsStillExist, format, args...)
 }
 
+// NewColumnReferencedByPrimaryKeyError is returned when attempting to drop a
+// column which is a part of the table's primary key.
+//
+// Note that this limitation is not fundamental; in postgres when dropping a
+// primary key column, it would silently drop the primary key constraint. At
+// the time of writing, cockroach does not permit dropping a primary key
+// constraint as it may require populating a new implicit rowid column for the
+// implicit primary key we use.
+func NewColumnReferencedByPrimaryKeyError(colName string) error {
+	return pgerror.Newf(pgcode.InvalidColumnReference,
+		"column %q is referenced by the primary key", colName)
+}
+
+// NewColumnReferencedByComputedColumnError is returned when dropping a column
+// and that column being dropped is referenced by a computed column. Note that
+// the cockroach behavior where this error is returned does not match the
+// postgres behavior.
+func NewColumnReferencedByComputedColumnError(droppingColumn, computedColumn string) error {
+	return pgerror.Newf(
+		pgcode.InvalidColumnReference,
+		"column %q is referenced by computed column %q",
+		droppingColumn,
+		computedColumn,
+	)
+}
+
+// NewUniqueConstraintReferencedByForeignKeyError generates an error to be
+// returned when dropping a unique constraint that is relied upon by an
+// inbound foreign key constraint.
+func NewUniqueConstraintReferencedByForeignKeyError(
+	uniqueConstraintOrIndexToDrop, tableName string,
+) error {
+	return pgerror.Newf(
+		pgcode.DependentObjectsStillExist,
+		"%q is referenced by foreign key from table %q",
+		uniqueConstraintOrIndexToDrop, tableName,
+	)
+}
+
 // NewRangeUnavailableError creates an unavailable range error.
 func NewRangeUnavailableError(rangeID roachpb.RangeID, origErr error) error {
 	return pgerror.Wrapf(origErr, pgcode.RangeUnavailable, "key range id:%d is unavailable", rangeID)

From f59548587a76571ec591d46786cacebbb375d881 Mon Sep 17 00:00:00 2001
From: Andrew Werner <awerner32@gmail.com>
Date: Mon, 18 Jul 2022 19:12:55 -0400
Subject: [PATCH 4/6] sql/rowenc: compute primary index encoding columns
 correctly

This commit ensures that the correct primary index entry is encoded when
building an entry for a primary index encoded index which does not include
every column in the table. This is the case when dropping a column using
the declarative schema changer.

Release note: None
---
 pkg/sql/rowenc/index_encoding.go | 41 ++++++++++++++++++++++++++++++--
 1 file changed, 39 insertions(+), 2 deletions(-)

diff --git a/pkg/sql/rowenc/index_encoding.go b/pkg/sql/rowenc/index_encoding.go
index c08c138a8e5a..e0db413be78c 100644
--- a/pkg/sql/rowenc/index_encoding.go
+++ b/pkg/sql/rowenc/index_encoding.go
@@ -1042,7 +1042,9 @@ func EncodePrimaryIndex(
 	if containsNull {
 		return nil, MakeNullPKError(tableDesc, index, colMap, values)
 	}
-	indexedColumns := index.CollectKeyColumnIDs()
+
+	storedColumns := getStoredColumnsForPrimaryIndex(index, colMap)
+
 	var entryValue []byte
 	indexEntries := make([]IndexEntry, 0, tableDesc.NumFamilies())
 	var columnsToEncode []valueEncodedColumn
@@ -1077,7 +1079,7 @@ func EncodePrimaryIndex(
 		}
 
 		for _, colID := range family.ColumnIDs {
-			if !indexedColumns.Contains(colID) {
+			if storedColumns.Contains(colID) {
 				columnsToEncode = append(columnsToEncode, valueEncodedColumn{id: colID})
 				continue
 			}
@@ -1113,6 +1115,41 @@ func EncodePrimaryIndex(
 	return indexEntries, nil
 }
 
+// getStoredColumnsForPrimaryIndex computes the set of columns stored in this
+// primary index's value for encoding. Note that EncodePrimaryIndex will utilize
+// this set to construct the value, but will augment this with the set of
+// key columns which are composite encoded; this is just the set of columns
+// stored in the primary index value which are not featured in the index key
+// whatsoever.
+//
+// colMap is expected to include all columns in the table.
+func getStoredColumnsForPrimaryIndex(
+	index catalog.Index, colMap catalog.TableColMap,
+) catalog.TableColSet {
+
+	// It should be rare to never that we come across an index which is encoded
+	// as a primary index but with a version older than this version.
+	// Nevertheless, for safety, we assume at that version that the stored
+	// columns set is not populated and instead we defer to the colMap to compute
+	// the complete set before subtracting the key columns.
+	if index.GetVersion() < descpb.PrimaryIndexWithStoredColumnsVersion {
+		var allColumn catalog.TableColSet
+		colMap.ForEach(func(colID descpb.ColumnID, _ int) {
+			allColumn.Add(colID)
+		})
+		return allColumn.Difference(index.CollectKeyColumnIDs())
+	}
+
+	// Note that the definition of Primary according to the catalog.Index method
+	// is that the index is installed as the primary index of the table, not
+	// that it has a primary index encoding. We must call the appropriate
+	// method based on this distinction to get the desired set of columns.
+	if !index.Primary() {
+		return index.CollectSecondaryStoredColumnIDs()
+	}
+	return index.CollectPrimaryStoredColumnIDs()
+}
+
 // MakeNullPKError generates an error when the value for a primary key column is
 // null.
 func MakeNullPKError(

From 89422e89e3f4e8b9f5cceb3450c291cb468034a6 Mon Sep 17 00:00:00 2001
From: Andrew Werner <awerner32@gmail.com>
Date: Mon, 18 Jul 2022 19:15:16 -0400
Subject: [PATCH 5/6] sql/logictest,execbuilder: update logic tests to avoid
 index IDs

These hard-coded index IDs embed assumptions which will be violated
by the new DROP COLUMN protocol.

Release note: None
---
 .../testdata/logic_test/numeric_references    | 16 ++++++++++++--
 pkg/sql/opt/exec/execbuilder/testdata/select  | 22 ++++++++++++++-----
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/pkg/sql/logictest/testdata/logic_test/numeric_references b/pkg/sql/logictest/testdata/logic_test/numeric_references
index c261f59158f2..fd724597b03a 100644
--- a/pkg/sql/logictest/testdata/logic_test/numeric_references
+++ b/pkg/sql/logictest/testdata/logic_test/numeric_references
@@ -94,15 +94,27 @@ SELECT * FROM [$num_ref_id(4,3,1) AS num_ref_alias]
 200  20  2
 300  30  3
 
+let $num_ref_bc
+SELECT index_id
+  FROM crdb_internal.table_indexes
+ WHERE descriptor_id = $num_ref_id
+   AND index_name = 'bc';
+
+let $num_ref_pkey
+SELECT index_id
+  FROM crdb_internal.table_indexes
+ WHERE descriptor_id = $num_ref_id
+   AND index_name = 'num_ref_pkey';
+
 query I rowsort
-SELECT * FROM [$num_ref_id(4) AS num_ref_alias]@[2]
+SELECT * FROM [$num_ref_id(4) AS num_ref_alias]@[$num_ref_bc]
 ----
 101
 200
 300
 
 query I rowsort
-SELECT * FROM [$num_ref_id(1) AS num_ref_alias]@[1]
+SELECT * FROM [$num_ref_id(1) AS num_ref_alias]@[$num_ref_pkey]
 ----
 1
 2
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/select b/pkg/sql/opt/exec/execbuilder/testdata/select
index 033e4d1b0e3f..59a9f3896be7 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/select
+++ b/pkg/sql/opt/exec/execbuilder/testdata/select
@@ -189,8 +189,18 @@ vectorized: true
   table: num_ref@bc
   spans: FULL SCAN
 
+let $num_ref_bc
+SELECT index_id
+  FROM crdb_internal.table_indexes
+ WHERE descriptor_id = $t_id AND index_name = 'bc';
+
+let $num_ref_pkey
+SELECT index_id
+  FROM crdb_internal.table_indexes
+ WHERE descriptor_id = $t_id AND index_name = 'num_ref_pkey';
+
 query T
-EXPLAIN (VERBOSE) SELECT * FROM [$t_id(1) AS num_ref_alias]@[1]
+EXPLAIN (VERBOSE) SELECT * FROM [$t_id(1) AS num_ref_alias]@[$num_ref_pkey]
 ----
 distribution: local
 vectorized: true
@@ -202,7 +212,7 @@ vectorized: true
   spans: FULL SCAN
 
 query T
-EXPLAIN (VERBOSE) SELECT * FROM [$t_id(1) AS num_ref_alias]@[2]
+EXPLAIN (VERBOSE) SELECT * FROM [$t_id(1) AS num_ref_alias]@[$num_ref_bc]
 ----
 distribution: local
 vectorized: true
@@ -214,7 +224,7 @@ vectorized: true
   spans: FULL SCAN
 
 query T
-EXPLAIN (VERBOSE) SELECT * FROM [$t_id(3) AS num_ref_alias]@[1]
+EXPLAIN (VERBOSE) SELECT * FROM [$t_id(3) AS num_ref_alias]@[$num_ref_pkey]
 ----
 distribution: local
 vectorized: true
@@ -226,7 +236,7 @@ vectorized: true
   spans: FULL SCAN
 
 query T
-EXPLAIN (VERBOSE) SELECT * FROM [$t_id(3) AS num_ref_alias]@[2]
+EXPLAIN (VERBOSE) SELECT * FROM [$t_id(3) AS num_ref_alias]@[$num_ref_bc]
 ----
 distribution: local
 vectorized: true
@@ -238,7 +248,7 @@ vectorized: true
   spans: FULL SCAN
 
 query T
-EXPLAIN (VERBOSE) SELECT * FROM [$t_id(4) AS num_ref_alias]@[1]
+EXPLAIN (VERBOSE) SELECT * FROM [$t_id(4) AS num_ref_alias]@[$num_ref_pkey]
 ----
 distribution: local
 vectorized: true
@@ -250,7 +260,7 @@ vectorized: true
   spans: FULL SCAN
 
 query T
-EXPLAIN (VERBOSE) SELECT * FROM [$t_id(4) AS num_ref_alias]@[2]
+EXPLAIN (VERBOSE) SELECT * FROM [$t_id(4) AS num_ref_alias]@[$num_ref_bc]
 ----
 distribution: local
 vectorized: true

From 07ce7b155892127bde9fff3d976897419d6cd97a Mon Sep 17 00:00:00 2001
From: Andrew Werner <awerner32@gmail.com>
Date: Mon, 18 Jul 2022 19:17:06 -0400
Subject: [PATCH 6/6] sql/schemachanger: implement `ALTER TABLE ... DROP
 COLUMN`

This is the initial implementation of `ALTER TABLE ... DROP COLUMN` in the
declarative schema changer. It explicitly does not have the case of adding
and dropping columns from the same table in the same transaction. It also
omits:

1) Dropping columns related to multi-region tables
2) Dropping columns with row-level TTLs
3) Dropping columns involved in UNIQUE WITHOUT INDEX constraints
4) Dropping columns involved in CHECK constraints
5) Dropping columns involved in FOREIGN KEY constraints

Fixes #84072.

Release note: None
---
 .../testdata/benchmark_expectations           |   6 +-
 pkg/ccl/changefeedccl/changefeed_test.go      |  11 +-
 .../schemafeed/testdata/drop_column           |  13 +-
 pkg/sql/as_of_test.go                         |   7 +-
 pkg/sql/backfill.go                           |   6 +-
 pkg/sql/catalog/descriptor.go                 |   3 +
 pkg/sql/catalog/table_elements.go             |  13 +-
 pkg/sql/catalog/tabledesc/index.go            |  12 +-
 pkg/sql/catalog/tabledesc/structured.go       |  27 +-
 .../logictest/testdata/logic_test/event_log   |   7 +-
 .../logictest/testdata/logic_test/sequences   |   4 +-
 pkg/sql/rowenc/index_encoding.go              |   4 +-
 pkg/sql/schema_changer_test.go                |  80 +-
 pkg/sql/schemachanger/BUILD.bazel             |   2 +-
 pkg/sql/schemachanger/scbuild/BUILD.bazel     |   1 +
 .../schemachanger/scbuild/builder_state.go    |   4 +-
 .../scbuild/internal/scbuildstmt/BUILD.bazel  |   1 +
 .../internal/scbuildstmt/alter_table.go       |   3 +-
 .../scbuildstmt/alter_table_add_column.go     |  19 +-
 .../scbuildstmt/alter_table_drop_column.go    | 622 ++++++++++++
 .../internal/scbuildstmt/create_index.go      |   6 +-
 .../internal/scbuildstmt/drop_index.go        |  14 +-
 .../scbuild/internal/scbuildstmt/helpers.go   |  25 +-
 .../scbuild/testdata/alter_table_drop_column  | 177 ++++
 .../testdata/unimplemented_alter_table        |  34 +-
 .../scplan/internal/scstage/build.go          |  37 +-
 pkg/sql/schemachanger/sctest/cumulative.go    |   8 +-
 .../testdata/end_to_end/drop_column_basic     | 517 ++++++++++
 .../end_to_end/drop_column_computed_index     | 631 ++++++++++++
 ...op_column_create_index_separate_statements | 930 ++++++++++++++++++
 .../end_to_end/drop_column_unique_index       | 550 +++++++++++
 .../end_to_end/drop_column_with_index         | 586 +++++++++++
 .../drop_multiple_columns_separate_statements | 790 +++++++++++++++
 .../testdata/explain/drop_column_basic        | 121 +++
 .../explain/drop_column_computed_index        | 145 +++
 ..._column_create_index_separate_statements.0 | 153 +++
 ..._column_create_index_separate_statements.1 | 188 ++++
 .../testdata/explain/drop_column_unique_index | 138 +++
 .../testdata/explain/drop_column_with_index   | 135 +++
 ...rop_multiple_columns_separate_statements.0 | 153 +++
 ...rop_multiple_columns_separate_statements.1 | 144 +++
 .../explain_verbose/drop_column_basic         | 473 +++++++++
 .../drop_column_computed_index                | 642 ++++++++++++
 ..._column_create_index_separate_statements.0 | 708 +++++++++++++
 ..._column_create_index_separate_statements.1 | 804 +++++++++++++++
 .../explain_verbose/drop_column_unique_index  | 582 +++++++++++
 .../explain_verbose/drop_column_with_index    | 572 +++++++++++
 ...rop_multiple_columns_separate_statements.0 | 708 +++++++++++++
 ...rop_multiple_columns_separate_statements.1 | 660 +++++++++++++
 49 files changed, 11366 insertions(+), 110 deletions(-)
 create mode 100644 pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_drop_column.go
 create mode 100644 pkg/sql/schemachanger/scbuild/testdata/alter_table_drop_column
 create mode 100644 pkg/sql/schemachanger/testdata/end_to_end/drop_column_basic
 create mode 100644 pkg/sql/schemachanger/testdata/end_to_end/drop_column_computed_index
 create mode 100644 pkg/sql/schemachanger/testdata/end_to_end/drop_column_create_index_separate_statements
 create mode 100644 pkg/sql/schemachanger/testdata/end_to_end/drop_column_unique_index
 create mode 100644 pkg/sql/schemachanger/testdata/end_to_end/drop_column_with_index
 create mode 100644 pkg/sql/schemachanger/testdata/end_to_end/drop_multiple_columns_separate_statements
 create mode 100644 pkg/sql/schemachanger/testdata/explain/drop_column_basic
 create mode 100644 pkg/sql/schemachanger/testdata/explain/drop_column_computed_index
 create mode 100644 pkg/sql/schemachanger/testdata/explain/drop_column_create_index_separate_statements.0
 create mode 100644 pkg/sql/schemachanger/testdata/explain/drop_column_create_index_separate_statements.1
 create mode 100644 pkg/sql/schemachanger/testdata/explain/drop_column_unique_index
 create mode 100644 pkg/sql/schemachanger/testdata/explain/drop_column_with_index
 create mode 100644 pkg/sql/schemachanger/testdata/explain/drop_multiple_columns_separate_statements.0
 create mode 100644 pkg/sql/schemachanger/testdata/explain/drop_multiple_columns_separate_statements.1
 create mode 100644 pkg/sql/schemachanger/testdata/explain_verbose/drop_column_basic
 create mode 100644 pkg/sql/schemachanger/testdata/explain_verbose/drop_column_computed_index
 create mode 100644 pkg/sql/schemachanger/testdata/explain_verbose/drop_column_create_index_separate_statements.0
 create mode 100644 pkg/sql/schemachanger/testdata/explain_verbose/drop_column_create_index_separate_statements.1
 create mode 100644 pkg/sql/schemachanger/testdata/explain_verbose/drop_column_unique_index
 create mode 100644 pkg/sql/schemachanger/testdata/explain_verbose/drop_column_with_index
 create mode 100644 pkg/sql/schemachanger/testdata/explain_verbose/drop_multiple_columns_separate_statements.0
 create mode 100644 pkg/sql/schemachanger/testdata/explain_verbose/drop_multiple_columns_separate_statements.1

diff --git a/pkg/bench/rttanalysis/testdata/benchmark_expectations b/pkg/bench/rttanalysis/testdata/benchmark_expectations
index f226235b5be3..94c2fdfef09b 100644
--- a/pkg/bench/rttanalysis/testdata/benchmark_expectations
+++ b/pkg/bench/rttanalysis/testdata/benchmark_expectations
@@ -15,9 +15,9 @@ exp,benchmark
 19,AlterTableConfigureZone/alter_table_configure_zone_5_replicas
 19,AlterTableConfigureZone/alter_table_configure_zone_7_replicas_
 19,AlterTableConfigureZone/alter_table_configure_zone_ranges
-14,AlterTableDropColumn/alter_table_drop_1_column
-15,AlterTableDropColumn/alter_table_drop_2_columns
-16,AlterTableDropColumn/alter_table_drop_3_columns
+18,AlterTableDropColumn/alter_table_drop_1_column
+18,AlterTableDropColumn/alter_table_drop_2_columns
+18,AlterTableDropColumn/alter_table_drop_3_columns
 13,AlterTableDropConstraint/alter_table_drop_1_check_constraint
 13,AlterTableDropConstraint/alter_table_drop_2_check_constraints
 13,AlterTableDropConstraint/alter_table_drop_3_check_constraints
diff --git a/pkg/ccl/changefeedccl/changefeed_test.go b/pkg/ccl/changefeedccl/changefeed_test.go
index e88deca7cac9..a25b98cadd64 100644
--- a/pkg/ccl/changefeedccl/changefeed_test.go
+++ b/pkg/ccl/changefeedccl/changefeed_test.go
@@ -2681,6 +2681,12 @@ func TestChangefeedStopOnSchemaChange(t *testing.T) {
 			})
 		})
 		t.Run("drop column", func(t *testing.T) {
+			// Sinkless feeds are not currently able to restart in the face of
+			// any schema changes. Dropping a column in the declarative schema
+			// changer means that an extra error will occur.
+			if _, isSinkless := f.(*sinklessFeedFactory); isSinkless {
+				skip.WithIssue(t, 84511)
+			}
 			sqlDB.Exec(t, `CREATE TABLE drop_column (a INT PRIMARY KEY, b INT)`)
 			defer sqlDB.Exec(t, `DROP TABLE drop_column`)
 			sqlDB.Exec(t, `INSERT INTO drop_column VALUES (0, NULL)`)
@@ -2697,12 +2703,7 @@ func TestChangefeedStopOnSchemaChange(t *testing.T) {
 			dropColumn = feed(t, f, `CREATE CHANGEFEED FOR drop_column `+
 				`WITH schema_change_events='column_changes', schema_change_policy='stop', cursor = '`+tsStr+`'`)
 			defer closeFeed(t, dropColumn)
-			// NB: You might expect to only see the new row here but we'll see them
-			// all because we cannot distinguish between the index backfill and
-			// foreground writes. See #35738.
 			assertPayloads(t, dropColumn, []string{
-				`drop_column: [0]->{"after": {"a": 0}}`,
-				`drop_column: [1]->{"after": {"a": 1}}`,
 				`drop_column: [2]->{"after": {"a": 2}}`,
 			})
 		})
diff --git a/pkg/ccl/changefeedccl/schemafeed/testdata/drop_column b/pkg/ccl/changefeedccl/schemafeed/testdata/drop_column
index df51ec2788fc..95a097d75abb 100644
--- a/pkg/ccl/changefeedccl/schemafeed/testdata/drop_column
+++ b/pkg/ccl/changefeedccl/schemafeed/testdata/drop_column
@@ -14,7 +14,12 @@ pop f=1
 ----
 t 1->2: DropColumn
 t 2->3: Unknown
-t 3->4: AddHiddenColumn
+t 3->4: Unknown
+t 4->5: Unknown
+t 5->6: Unknown
+t 6->7: PrimaryKeyChange (no column changes)
+t 7->8: Unknown
+t 8->9: AddHiddenColumn
 
 exec
 SET use_declarative_schema_changer=off;
@@ -23,6 +28,6 @@ ALTER TABLE t DROP COLUMN k;
 
 pop f=1
 ----
-t 4->5: DropColumn
-t 5->6: Unknown
-t 6->7: AddHiddenColumn
+t 9->10: DropColumn
+t 10->11: Unknown
+t 11->12: AddHiddenColumn
diff --git a/pkg/sql/as_of_test.go b/pkg/sql/as_of_test.go
index 3f799543cfad..d148e419eafa 100644
--- a/pkg/sql/as_of_test.go
+++ b/pkg/sql/as_of_test.go
@@ -36,10 +36,15 @@ func TestAsOfTime(t *testing.T) {
 	defer leaktest.AfterTest(t)()
 	defer log.Scope(t).Close(t)
 
+	ctx, cancel := context.WithCancel(context.Background())
 	params, _ := tests.CreateTestServerParams()
-	params.Knobs.GCJob = &sql.GCJobTestingKnobs{RunBeforeResume: func(_ jobspb.JobID) error { select {} }}
+	params.Knobs.GCJob = &sql.GCJobTestingKnobs{RunBeforeResume: func(_ jobspb.JobID) error {
+		<-ctx.Done()
+		return nil
+	}}
 	s, db, _ := serverutils.StartServer(t, params)
 	defer s.Stopper().Stop(context.Background())
+	defer cancel()
 
 	const val1 = 1
 	const val2 = 2
diff --git a/pkg/sql/backfill.go b/pkg/sql/backfill.go
index 716afb033b9f..97736aa3083c 100644
--- a/pkg/sql/backfill.go
+++ b/pkg/sql/backfill.go
@@ -1800,7 +1800,7 @@ func populateExpectedCounts(
 		// in-memory copy of the descriptor and add it to the Collection's synthetic
 		// descriptors, so that we can use SQL below to perform the validation.
 		fakeDesc, err := tableDesc.MakeFirstMutationPublic(
-			catalog.IgnoreConstraints, catalog.IgnorePKSwaps,
+			catalog.IgnoreConstraints, catalog.IgnorePKSwaps, catalog.RetainDroppingColumns,
 		)
 		if err != nil {
 			return 0, err
@@ -1891,7 +1891,9 @@ func countIndexRowsAndMaybeCheckUniqueness(
 		// Make the mutations public in an in-memory copy of the descriptor and
 		// add it to the Collection's synthetic descriptors, so that we can use
 		// SQL below to perform the validation.
-		fakeDesc, err := tableDesc.MakeFirstMutationPublic(catalog.IgnoreConstraints)
+		fakeDesc, err := tableDesc.MakeFirstMutationPublic(
+			catalog.IgnoreConstraints, catalog.RetainDroppingColumns,
+		)
 		if err != nil {
 			return 0, err
 		}
diff --git a/pkg/sql/catalog/descriptor.go b/pkg/sql/catalog/descriptor.go
index 0ccd7e5a13d9..13c6bb8aaeec 100644
--- a/pkg/sql/catalog/descriptor.go
+++ b/pkg/sql/catalog/descriptor.go
@@ -60,6 +60,9 @@ const (
 	// IgnorePKSwaps is used in MakeFirstMutationPublic to indicate that the
 	// table descriptor returned should include newly added constraints.
 	IgnorePKSwaps
+	// RetainDroppingColumns is used in MakeFirstMutationPublic to indicate that
+	// the table descriptor should include newly dropped columns.
+	RetainDroppingColumns
 )
 
 // DescriptorBuilder interfaces are used to build catalog.Descriptor
diff --git a/pkg/sql/catalog/table_elements.go b/pkg/sql/catalog/table_elements.go
index 7a3e072ea5ab..746c5ec93629 100644
--- a/pkg/sql/catalog/table_elements.go
+++ b/pkg/sql/catalog/table_elements.go
@@ -201,13 +201,15 @@ type Index interface {
 	NumCompositeColumns() int
 	GetCompositeColumnID(compositeColumnOrdinal int) descpb.ColumnID
 	UseDeletePreservingEncoding() bool
-	// ForcePut, if true, forces all writes to use Put rather than CPut or InitPut.
+	// ForcePut forces all writes to use Put rather than CPut or InitPut.
 	//
 	// Users of this options should take great care as it
 	// effectively mean unique constraints are not respected.
 	//
-	// Currently (2022-01-19) this two users: delete preserving
-	// indexes and merging indexes.
+	// Currently (2022-07-15) there are three users:
+	//   * delete preserving indexes
+	//   * merging indexes
+	//   * dropping primary indexes
 	//
 	// Delete preserving encoding indexes are used only as a log of
 	// index writes during backfill, thus we can blindly put values into
@@ -218,6 +220,11 @@ type Index interface {
 	// are merged into the index. Uniqueness for such indexes is
 	// checked by the schema changer before they are brought back
 	// online.
+	//
+	// In the case of dropping primary indexes, we always ensure that
+	// there's a replacement primary index which has become public.
+	// The reason we must not use cput is that the new primary index
+	// may not store all the columns stored in this index.
 	ForcePut() bool
 
 	// CreatedAt is an approximate timestamp at which the index was created.
diff --git a/pkg/sql/catalog/tabledesc/index.go b/pkg/sql/catalog/tabledesc/index.go
index d81703468d4b..78b3183041f8 100644
--- a/pkg/sql/catalog/tabledesc/index.go
+++ b/pkg/sql/catalog/tabledesc/index.go
@@ -363,11 +363,15 @@ func (w index) UseDeletePreservingEncoding() bool {
 }
 
 // ForcePut returns true if writes to the index should only use Put (rather than
-// CPut or InitPut). This is used by indexes currently being built by the
-// MVCC-compliant index backfiller and the temporary indexes that support that
-// process.
+// CPut or InitPut). This is used by:
+//
+//  * indexes currently being built by the MVCC-compliant index backfiller, and
+//  * the temporary indexes that support that process, and
+//  * old primary indexes which are being dropped.
+//
 func (w index) ForcePut() bool {
-	return w.Merging() || w.desc.UseDeletePreservingEncoding
+	return w.Merging() || w.desc.UseDeletePreservingEncoding ||
+		w.Dropped() && w.IsUnique() && w.GetEncodingType() == descpb.PrimaryIndexEncoding
 }
 
 func (w index) CreatedAt() time.Time {
diff --git a/pkg/sql/catalog/tabledesc/structured.go b/pkg/sql/catalog/tabledesc/structured.go
index 1cf5fa9a435b..b381ddf16d15 100644
--- a/pkg/sql/catalog/tabledesc/structured.go
+++ b/pkg/sql/catalog/tabledesc/structured.go
@@ -2239,6 +2239,7 @@ func (desc *wrapper) MakeFirstMutationPublic(
 	mutationID := desc.Mutations[0].MutationID
 	i := 0
 	policy := makeMutationPublicationPolicy(filters...)
+	var clone []descpb.DescriptorMutation
 	for _, mutation := range desc.Mutations {
 		if mutation.MutationID != mutationID {
 			// Mutations are applied in a FIFO order. Only apply the first set
@@ -2246,14 +2247,19 @@ func (desc *wrapper) MakeFirstMutationPublic(
 			break
 		}
 		i++
-		if policy.shouldSkip(&mutation) {
-			continue
-		}
-		if err := table.MakeMutationComplete(mutation); err != nil {
-			return nil, err
+		switch {
+		case policy.shouldSkip(&mutation):
+			// Don't add to clone.
+		case policy.shouldRetain(&mutation):
+			mutation.Direction = descpb.DescriptorMutation_ADD
+			fallthrough
+		default:
+			if err := table.MakeMutationComplete(mutation); err != nil {
+				return nil, err
+			}
 		}
 	}
-	table.Mutations = table.Mutations[i:]
+	table.Mutations = append(clone, table.Mutations[i:]...)
 	table.Version++
 	return table, nil
 }
@@ -2287,6 +2293,15 @@ func (p mutationPublicationPolicy) shouldSkip(m *descpb.DescriptorMutation) bool
 	}
 }
 
+func (p mutationPublicationPolicy) shouldRetain(m *descpb.DescriptorMutation) bool {
+	switch {
+	case m.GetColumn() != nil && m.Direction == descpb.DescriptorMutation_DROP:
+		return p.includes(catalog.RetainDroppingColumns)
+	default:
+		return false
+	}
+}
+
 // MakePublic implements the TableDescriptor interface.
 func (desc *wrapper) MakePublic() catalog.TableDescriptor {
 	// Clone the ImmutableTable descriptor because we want to create an ImmutableCopy one.
diff --git a/pkg/sql/logictest/testdata/logic_test/event_log b/pkg/sql/logictest/testdata/logic_test/event_log
index 0bd22b87e4c6..9ebdd516988b 100644
--- a/pkg/sql/logictest/testdata/logic_test/event_log
+++ b/pkg/sql/logictest/testdata/logic_test/event_log
@@ -1063,8 +1063,11 @@ CREATE VIEW z AS SELECT b FROM x
 statement ok
 DROP TABLE x CASCADE
 
+
+# Note that the CascadedDroppedViews field should be populated. It is omitted
+# temporarily because of #84206.
 query IT
-SELECT "reportingID", info::JSONB - 'Timestamp' - 'DescriptorID'
+SELECT "reportingID", info::JSONB - 'Timestamp' - 'DescriptorID' - 'CascadedDroppedViews'
 FROM system.eventlog
 WHERE "eventType" = 'drop_table'
 ORDER BY "timestamp" DESC, info
@@ -1112,4 +1115,4 @@ WHERE "eventType" = 'alter_table'
 ORDER BY "timestamp" DESC, info
 LIMIT 1
 ----
-1  {"CascadeDroppedViews": ["defaultdb.public.v", "defaultdb.public.vv"], "EventType": "alter_table", "MutationID": 1, "Statement": "ALTER TABLE defaultdb.public.x DROP COLUMN b CASCADE", "TableName": "defaultdb.public.x", "Tag": "ALTER TABLE", "User": "root"}
+1  {"EventType": "alter_table", "MutationID": 1, "Statement": "ALTER TABLE defaultdb.public.x DROP COLUMN b CASCADE", "TableName": "defaultdb.public.x", "Tag": "ALTER TABLE", "User": "root"}
diff --git a/pkg/sql/logictest/testdata/logic_test/sequences b/pkg/sql/logictest/testdata/logic_test/sequences
index 48796e51c8f0..ab2c1cc2c470 100644
--- a/pkg/sql/logictest/testdata/logic_test/sequences
+++ b/pkg/sql/logictest/testdata/logic_test/sequences
@@ -1131,7 +1131,7 @@ CREATE TABLE ab(a INT DEFAULT nextval('owned_seq'), b INT DEFAULT nextval('owned
 statement ok
 ALTER SEQUENCE owned_seq OWNED BY ab.a;
 
-statement error cannot drop table ab because other objects depend on it
+statement error cannot drop column a because other objects depend on it
 ALTER TABLE ab DROP COLUMN a;
 
 statement ok
@@ -1186,7 +1186,7 @@ CREATE TABLE b(b INT DEFAULT nextval('seq'));
 statement error cannot drop table a because other objects depend on it
 DROP TABLE a
 
-statement error cannot drop table a because other objects depend on it
+statement error cannot drop column a because other objects depend on it
 ALTER TABLE a DROP COLUMN a;
 
 statement ok
diff --git a/pkg/sql/rowenc/index_encoding.go b/pkg/sql/rowenc/index_encoding.go
index e0db413be78c..181655eefee7 100644
--- a/pkg/sql/rowenc/index_encoding.go
+++ b/pkg/sql/rowenc/index_encoding.go
@@ -1130,8 +1130,8 @@ func getStoredColumnsForPrimaryIndex(
 	// It should be rare to never that we come across an index which is encoded
 	// as a primary index but with a version older than this version.
 	// Nevertheless, for safety, we assume at that version that the stored
-	// columns set is not populated and instead we defer to the colMap to compute
-	// the complete set before subtracting the key columns.
+	// columns set is not populated, and instead we defer to the colMap to
+	// compute the complete set before subtracting the key columns.
 	if index.GetVersion() < descpb.PrimaryIndexWithStoredColumnsVersion {
 		var allColumn catalog.TableColSet
 		colMap.ForEach(func(colID descpb.ColumnID, _ int) {
diff --git a/pkg/sql/schema_changer_test.go b/pkg/sql/schema_changer_test.go
index 65800aaccc3a..6c71cd5f67ba 100644
--- a/pkg/sql/schema_changer_test.go
+++ b/pkg/sql/schema_changer_test.go
@@ -346,48 +346,46 @@ func runSchemaChangeWithOperations(
 	// Run a variety of operations during the backfill.
 	ctx := context.Background()
 
+	conn, err := sqlDB.Conn(ctx)
+	require.NoError(t, err)
+	defer func() { assert.NoError(t, conn.Close()) }()
+	exec := func(sql string, args ...interface{}) {
+		t.Helper()
+		_, err := conn.ExecContext(ctx, sql, args...)
+		if err != nil {
+			t.Error(err)
+		}
+	}
 	// Update some rows.
 	var updatedKeys []int
 	for i := 0; i < 10; i++ {
 		k := rand.Intn(maxValue)
 		v := maxValue + i + 1
-		if _, err := sqlDB.Exec(`UPDATE t.test SET v = $1 WHERE k = $2`, v, k); err != nil {
-			t.Error(err)
-		}
+		exec(`UPDATE t.test SET v = $1 WHERE k = $2`, v, k)
 		updatedKeys = append(updatedKeys, k)
 	}
 
 	// Reupdate updated values back to what they were before.
 	for _, k := range updatedKeys {
 		if rand.Float32() < 0.5 || !useUpsert {
-			if _, err := sqlDB.Exec(`UPDATE t.test SET v = $1 WHERE k = $2`, maxValue-k, k); err != nil {
-				t.Error(err)
-			}
+			exec(`UPDATE t.test SET v = $1 WHERE k = $2`, maxValue-k, k)
 		} else {
-			if _, err := sqlDB.Exec(`UPSERT INTO t.test (k,v) VALUES ($1, $2)`, k, maxValue-k); err != nil {
-				t.Error(err)
-			}
+			exec(`UPSERT INTO t.test (k,v) VALUES ($1, $2)`, k, maxValue-k)
 		}
 	}
 
 	// Delete some rows.
 	deleteStartKey := rand.Intn(maxValue - 10)
 	for i := 0; i < 10; i++ {
-		if _, err := sqlDB.Exec(`DELETE FROM t.test WHERE k = $1`, deleteStartKey+i); err != nil {
-			t.Error(err)
-		}
+		exec(`DELETE FROM t.test WHERE k = $1`, deleteStartKey+i)
 	}
 	// Reinsert deleted rows.
 	for i := 0; i < 10; i++ {
 		k := deleteStartKey + i
 		if rand.Float32() < 0.5 || !useUpsert {
-			if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES($1, $2)`, k, maxValue-k); err != nil {
-				t.Error(err)
-			}
+			exec(`INSERT INTO t.test VALUES($1, $2)`, k, maxValue-k)
 		} else {
-			if _, err := sqlDB.Exec(`UPSERT INTO t.test VALUES($1, $2)`, k, maxValue-k); err != nil {
-				t.Error(err)
-			}
+			exec(`UPSERT INTO t.test VALUES($1, $2)`, k, maxValue-k)
 		}
 	}
 
@@ -395,17 +393,15 @@ func runSchemaChangeWithOperations(
 	numInserts := 10
 	for i := 0; i < numInserts; i++ {
 		k := maxValue + i + 1
-		if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES($1, $1)`, k); err != nil {
-			t.Error(err)
-		}
+		exec(`INSERT INTO t.test VALUES($1, $1)`, k)
 	}
 
 	wg.Wait() // for schema change to complete.
 
 	// Verify the number of keys left behind in the table to
 	// validate schema change operations. We wait for any SCHEMA
-	// CHANGE GC jobs to complete to ensure our key count doesn't
-	// include keys from a temporary index.
+	// CHANGE GC jobs for temp indexes to show that the temp index
+	// has been cleared.
 	if _, err := sqlDB.Exec(`SHOW JOBS WHEN COMPLETE (SELECT job_id FROM [SHOW JOBS] WHERE job_type = 'SCHEMA CHANGE GC')`); err != nil {
 		t.Fatal(err)
 	}
@@ -590,8 +586,6 @@ func TestRaceWithBackfill(t *testing.T) {
 		SQLSchemaChanger: &sql.SchemaChangerTestingKnobs{
 			BackfillChunkSize: chunkSize,
 		},
-		// Disable GC job.
-		// GCJob: &sql.GCJobTestingKnobs{RunBeforeResume: func(_ jobspb.JobID) error { select {} }},
 		DistSQL: &execinfra.TestingKnobs{
 			RunBeforeBackfillChunk: func(sp roachpb.Span) error {
 				notifyBackfill()
@@ -616,14 +610,15 @@ CREATE UNIQUE INDEX vidx ON t.test (v);
 `); err != nil {
 		t.Fatal(err)
 	}
-
+	tableDesc := desctestutils.TestingGetPublicTableDescriptor(kvDB, keys.SystemSQLCodec, "t", "test")
+	// Add a zone config for the table so that garbage collection happens rapidly.
+	if _, err := sqltestutils.AddImmediateGCZoneConfig(sqlDB, tableDesc.GetID()); err != nil {
+		t.Fatal(err)
+	}
 	// Bulk insert.
 	if err := sqltestutils.BulkInsertIntoTable(sqlDB, maxValue); err != nil {
 		t.Fatal(err)
 	}
-
-	// Split the table into multiple ranges.
-	tableDesc := desctestutils.TestingGetPublicTableDescriptor(kvDB, keys.SystemSQLCodec, "t", "test")
 	var sps []sql.SplitPoint
 	for i := 1; i <= numNodes-1; i++ {
 		sps = append(sps, sql.SplitPoint{TargetNodeIdx: i, Vals: []interface{}{maxValue / numNodes * i}})
@@ -2181,6 +2176,7 @@ func TestAddColumnDuringColumnDrop(t *testing.T) {
 	backfillNotification := make(chan struct{})
 	continueBackfillNotification := make(chan struct{})
 	params.Knobs = base.TestingKnobs{
+
 		SQLSchemaChanger: &sql.SchemaChangerTestingKnobs{
 			RunBeforeBackfill: func() error {
 				if backfillNotification != nil {
@@ -2219,14 +2215,20 @@ CREATE TABLE t.test (
 	var wg sync.WaitGroup
 	wg.Add(1)
 	go func() {
-		if _, err := sqlDB.Exec(`ALTER TABLE t.test DROP column v;`); err != nil {
+		if _, err := sqlDB.Exec(`
+SET use_declarative_schema_changer = off;
+ALTER TABLE t.test DROP column v;
+`); err != nil {
 			t.Error(err)
 		}
 		wg.Done()
 	}()
 
 	<-notification
-	if _, err := sqlDB.Exec(`ALTER TABLE t.test ADD column v INT DEFAULT 0;`); !testutils.IsError(err, `column "v" being dropped, try again later`) {
+	if _, err := sqlDB.Exec(`
+SET use_declarative_schema_changer = off;
+ALTER TABLE t.test ADD column v INT DEFAULT 0;
+`); !testutils.IsError(err, `column "v" being dropped, try again later`) {
 		t.Fatal(err)
 	}
 
@@ -2241,6 +2243,10 @@ CREATE TABLE t.test (
 // Test a DROP failure on a unique column. The rollback
 // process might not be able to reconstruct the index and thus
 // purges the rollback. For now this is considered acceptable.
+//
+// TODO(ajwerner): This test is not relevant in the declarative schema
+// changer; in the declarative schema changer we don't stop upholding
+// the constraint too soon.
 func TestSchemaUniqueColumnDropFailure(t *testing.T) {
 	defer leaktest.AfterTest(t)()
 	defer log.Scope(t).Close(t)
@@ -2318,7 +2324,11 @@ CREATE TABLE t.test (k INT PRIMARY KEY, v INT UNIQUE DEFAULT 23 CREATE FAMILY F3
 	go func() {
 		defer wg.Done()
 		// This query stays blocked until the end of the test.
-		_, _ = sqlDB.Exec(`ALTER TABLE t.test DROP column v`)
+		// Note that we must use the legacy schema changer because this test
+		// uses knobs that don't make sense in the declarative schema changer.
+		_, _ = sqlDB.Exec(`
+SET use_declarative_schema_changer = off;
+ALTER TABLE t.test DROP column v`)
 	}()
 
 	// Wait until the job is reverted.
@@ -6112,6 +6122,8 @@ ALTER TABLE t.test2 ADD FOREIGN KEY (k) REFERENCES t.test;
 // job, after reversing the mutations the job is set up to throw an error so
 // that mutations are attempted to be reverted again. The mutation shouldn't be
 // attempted to be reversed twice.
+//
+// NOTE: This test only exercises the legacy schema changer.
 func TestMultipleRevert(t *testing.T) {
 	defer leaktest.AfterTest(t)()
 	defer log.Scope(t).Close(t)
@@ -6178,7 +6190,9 @@ func TestMultipleRevert(t *testing.T) {
 	runner.Exec(t, `CREATE DATABASE t;`)
 	runner.Exec(t, `CREATE TABLE t.test (k INT PRIMARY KEY, v INT8);`)
 	runner.Exec(t, `INSERT INTO t.test VALUES (1, 2);`)
-	runner.ExpectErr(t, "job canceled by user", `ALTER TABLE t.public.test DROP COLUMN v;`)
+	runner.ExpectErr(t, "job canceled by user", `
+SET use_declarative_schema_changer = off;
+ALTER TABLE t.public.test DROP COLUMN v;`)
 
 	// Ensure that the schema change was rolled back.
 	rows := runner.QueryStr(t, "SELECT * FROM t.test")
diff --git a/pkg/sql/schemachanger/BUILD.bazel b/pkg/sql/schemachanger/BUILD.bazel
index b09113e13465..c8ffa472e7c1 100644
--- a/pkg/sql/schemachanger/BUILD.bazel
+++ b/pkg/sql/schemachanger/BUILD.bazel
@@ -9,7 +9,7 @@ filegroup(
 
 go_test(
     name = "schemachanger_test",
-    size = "medium",
+    size = "large",
     srcs = [
         "end_to_end_test.go",
         "main_test.go",
diff --git a/pkg/sql/schemachanger/scbuild/BUILD.bazel b/pkg/sql/schemachanger/scbuild/BUILD.bazel
index a82101fba8e2..3761bc5fb4a7 100644
--- a/pkg/sql/schemachanger/scbuild/BUILD.bazel
+++ b/pkg/sql/schemachanger/scbuild/BUILD.bazel
@@ -20,6 +20,7 @@ go_library(
         "//pkg/settings/cluster",
         "//pkg/sql/catalog",
         "//pkg/sql/catalog/catpb",
+        "//pkg/sql/catalog/colinfo",
         "//pkg/sql/catalog/descpb",
         "//pkg/sql/catalog/descs",
         "//pkg/sql/catalog/resolver",
diff --git a/pkg/sql/schemachanger/scbuild/builder_state.go b/pkg/sql/schemachanger/scbuild/builder_state.go
index 6243f1803c90..86e300a6a198 100644
--- a/pkg/sql/schemachanger/scbuild/builder_state.go
+++ b/pkg/sql/schemachanger/scbuild/builder_state.go
@@ -18,6 +18,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/security/username"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/catpb"
+	"github.com/cockroachdb/cockroach/pkg/sql/catalog/colinfo"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/schemadesc"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/schemaexpr"
@@ -804,8 +805,7 @@ func (b *builderState) ResolveColumn(
 		if p.IsExistenceOptional {
 			return nil
 		}
-		panic(pgerror.Newf(pgcode.UndefinedColumn,
-			"column %q not found in relation %q", columnName, rel.GetName()))
+		panic(colinfo.NewUndefinedColumnError(string(columnName)))
 	}
 	return c.ers.Filter(func(_ scpb.Status, _ scpb.TargetStatus, e scpb.Element) bool {
 		idI, _ := screl.Schema.GetAttribute(screl.ColumnID, e)
diff --git a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/BUILD.bazel b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/BUILD.bazel
index 20b643210a57..049985121e4c 100644
--- a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/BUILD.bazel
+++ b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/BUILD.bazel
@@ -6,6 +6,7 @@ go_library(
     srcs = [
         "alter_table.go",
         "alter_table_add_column.go",
+        "alter_table_drop_column.go",
         "comment_on.go",
         "create_index.go",
         "dependencies.go",
diff --git a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table.go b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table.go
index c8fe90791e61..51413905506d 100644
--- a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table.go
+++ b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table.go
@@ -28,7 +28,8 @@ import (
 // declarative schema  changer. Operations marked as non-fully supported can
 // only be with the use_declarative_schema_changer session variable.
 var supportedAlterTableStatements = map[reflect.Type]supportedStatement{
-	reflect.TypeOf((*tree.AlterTableAddColumn)(nil)): {alterTableAddColumn, true},
+	reflect.TypeOf((*tree.AlterTableAddColumn)(nil)):  {alterTableAddColumn, true},
+	reflect.TypeOf((*tree.AlterTableDropColumn)(nil)): {alterTableDropColumn, true},
 }
 
 func init() {
diff --git a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_add_column.go b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_add_column.go
index 1f7abc1b2c9d..25a4cac6a149 100644
--- a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_add_column.go
+++ b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_add_column.go
@@ -226,7 +226,7 @@ func alterTableAddColumn(
 	// Add secondary indexes for this column.
 	var primaryIdx *scpb.PrimaryIndex
 
-	if newPrimary := addColumn(b, spec); newPrimary != nil {
+	if newPrimary := addColumn(b, spec, t); newPrimary != nil {
 		primaryIdx = newPrimary
 	} else {
 		publicTargets := b.QueryByID(tbl.TableID).Filter(
@@ -278,7 +278,7 @@ type addColumnSpec struct {
 
 // addColumn is a helper function which adds column element targets and ensures
 // that the new column is backed by a primary index, which it returns.
-func addColumn(b BuildCtx, spec addColumnSpec) (backing *scpb.PrimaryIndex) {
+func addColumn(b BuildCtx, spec addColumnSpec, n tree.NodeFormatter) (backing *scpb.PrimaryIndex) {
 	b.Add(spec.col)
 	if spec.fam != nil {
 		b.Add(spec.fam)
@@ -303,7 +303,7 @@ func addColumn(b BuildCtx, spec addColumnSpec) (backing *scpb.PrimaryIndex) {
 	tableID := spec.tbl.TableID
 	existing, freshlyAdded := getPrimaryIndexes(b, tableID)
 	if freshlyAdded != nil {
-		handleAddColumnFreshlyAddedPrimaryIndex(b, spec, freshlyAdded)
+		handleAddColumnFreshlyAddedPrimaryIndex(b, spec, freshlyAdded, n)
 		return freshlyAdded
 	}
 
@@ -373,12 +373,21 @@ func addColumn(b BuildCtx, spec addColumnSpec) (backing *scpb.PrimaryIndex) {
 // table and a previous command has already created a new primary index. In
 // this situation, we need to add the new column to this new primary index.
 func handleAddColumnFreshlyAddedPrimaryIndex(
-	b BuildCtx, spec addColumnSpec, freshlyAdded *scpb.PrimaryIndex,
+	b BuildCtx, spec addColumnSpec, freshlyAdded *scpb.PrimaryIndex, n tree.NodeFormatter,
 ) {
-	// TODO(ajwerner): Make sure we aren't removing any columns from this index.
+	// Check to make sure we aren't removing any columns from this index.
 	// If we are, it means that this transaction is both adding and removing
 	// physical columns from the table, and we need an intermediate, transient
 	// primary index.
+	//
+	// TODO(ajwerner): Handle adding and dropping columns in the same statement
+	// and transaction.
+	if haveDroppingColumn := !b.QueryByID(freshlyAdded.TableID).
+		Filter(isColumnFilter).
+		Filter(absentTargetFilter).
+		IsEmpty(); haveDroppingColumn {
+		panic(scerrors.NotImplementedErrorf(n, "DROP COLUMN after ADD COLUMN"))
+	}
 
 	var tempIndex *scpb.TemporaryIndex
 	scpb.ForEachTemporaryIndex(b.QueryByID(spec.tbl.TableID), func(
diff --git a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_drop_column.go b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_drop_column.go
new file mode 100644
index 000000000000..d3eb0cfabe3a
--- /dev/null
+++ b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_drop_column.go
@@ -0,0 +1,622 @@
+// Copyright 2022 The Cockroach Authors.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+package scbuildstmt
+
+import (
+	"sort"
+
+	"github.com/cockroachdb/cockroach/pkg/sql/catalog"
+	"github.com/cockroachdb/cockroach/pkg/sql/catalog/colinfo"
+	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
+	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgcode"
+	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgerror"
+	"github.com/cockroachdb/cockroach/pkg/sql/privilege"
+	"github.com/cockroachdb/cockroach/pkg/sql/schemachanger/scerrors"
+	"github.com/cockroachdb/cockroach/pkg/sql/schemachanger/scpb"
+	"github.com/cockroachdb/cockroach/pkg/sql/schemachanger/screl"
+	"github.com/cockroachdb/cockroach/pkg/sql/sem/catid"
+	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
+	"github.com/cockroachdb/cockroach/pkg/sql/sqlerrors"
+	"github.com/cockroachdb/cockroach/pkg/util/protoutil"
+	"github.com/cockroachdb/errors"
+)
+
+func alterTableDropColumn(
+	b BuildCtx, tn *tree.TableName, tbl *scpb.Table, n *tree.AlterTableDropColumn,
+) {
+	checkSafeUpdatesForDropColumn(b)
+	checkRowLevelTTLColumn(b, tn, tbl, n)
+	checkRegionalByRowColumnConflict(b, tbl, n)
+	b.IncrementSchemaChangeAlterCounter("table", "drop_column")
+	col, elts, done := resolveColumnForDropColumn(b, tn, tbl, n)
+	if done {
+		return
+	}
+	checkColumnNotInaccessible(col, n)
+	dropColumn(b, tn, tbl, n, col, elts, n.DropBehavior)
+}
+
+func checkSafeUpdatesForDropColumn(b BuildCtx) {
+	if !b.SessionData().SafeUpdates {
+		return
+	}
+	err := pgerror.DangerousStatementf("ALTER TABLE DROP COLUMN will " +
+		"remove all data in that column")
+	if !b.EvalCtx().TxnIsSingleStmt {
+		err = errors.WithIssueLink(err, errors.IssueLink{
+			IssueURL: "https://github.com/cockroachdb/cockroach/issues/46541",
+			Detail: "when used in an explicit transaction combined with other " +
+				"schema changes to the same table, DROP COLUMN can result in data " +
+				"loss if one of the other schema change fails or is canceled",
+		})
+	}
+	panic(err)
+}
+
+func checkRowLevelTTLColumn(
+	b BuildCtx, tn *tree.TableName, tbl *scpb.Table, n *tree.AlterTableDropColumn,
+) {
+	var rowLevelTTL *scpb.RowLevelTTL
+	publicTargets := b.QueryByID(tbl.TableID).Filter(publicTargetFilter)
+	scpb.ForEachRowLevelTTL(publicTargets, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.RowLevelTTL,
+	) {
+		rowLevelTTL = e
+	})
+	if n.Column == colinfo.TTLDefaultExpirationColumnName && rowLevelTTL != nil {
+		panic(errors.WithHintf(
+			pgerror.Newf(
+				pgcode.InvalidTableDefinition,
+				`cannot drop column %s while row-level TTL is active`,
+				n.Column,
+			),
+			"use ALTER TABLE %s RESET (ttl) instead",
+			tn,
+		))
+	}
+}
+
+func checkRegionalByRowColumnConflict(b BuildCtx, tbl *scpb.Table, n *tree.AlterTableDropColumn) {
+	var regionalByRow *scpb.TableLocalityRegionalByRow
+	// TODO(ajwerner): Does this need to look at status or target status?
+	scpb.ForEachTableLocalityRegionalByRow(b.QueryByID(tbl.TableID), func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.TableLocalityRegionalByRow,
+	) {
+		regionalByRow = e
+	})
+	if regionalByRow == nil {
+		return
+	}
+	rbrColName := tree.RegionalByRowRegionDefaultColName
+	if regionalByRow.As != "" {
+		rbrColName = tree.Name(regionalByRow.As)
+	}
+	if rbrColName == n.Column {
+		panic(errors.WithHintf(
+			pgerror.Newf(
+				pgcode.InvalidColumnReference,
+				"cannot drop column %s as it is used to store the region in a REGIONAL BY ROW table",
+				n.Column,
+			),
+			"You must change the table locality before dropping this table or alter the table to use a different column to use for the region.",
+		))
+	}
+	// TODO(ajwerner): Support dropping a column of a REGIONAL BY ROW table.
+	panic(scerrors.NotImplementedErrorf(n,
+		"regional by row partitioning is not supported"))
+}
+
+func resolveColumnForDropColumn(
+	b BuildCtx, tn *tree.TableName, tbl *scpb.Table, n *tree.AlterTableDropColumn,
+) (col *scpb.Column, elts ElementResultSet, done bool) {
+	elts = b.ResolveColumn(tbl.TableID, n.Column, ResolveParams{
+		IsExistenceOptional: n.IfExists,
+		RequiredPrivilege:   privilege.CREATE,
+	})
+	var colTargetStatus scpb.TargetStatus
+	_, colTargetStatus, col = scpb.FindColumn(elts)
+	if col == nil || colTargetStatus == scpb.ToAbsent {
+		if !n.IfExists {
+			panic(errors.AssertionFailedf("failed to find column %v in %v which was already resolved",
+				n.Column, tn))
+		}
+		return nil, nil, true
+	}
+	return col, elts, false
+}
+
+func checkColumnNotInaccessible(col *scpb.Column, n *tree.AlterTableDropColumn) {
+	if col.IsInaccessible {
+		panic(pgerror.Newf(
+			pgcode.InvalidColumnReference,
+			"cannot drop inaccessible column %q",
+			n.Column,
+		))
+	}
+}
+
+func dropColumn(
+	b BuildCtx,
+	tn *tree.TableName,
+	tbl *scpb.Table,
+	n tree.NodeFormatter,
+	col *scpb.Column,
+	colElts ElementResultSet,
+	behavior tree.DropBehavior,
+) {
+	_, _, cn := scpb.FindColumnName(colElts)
+	_, _, ct := scpb.FindColumnType(colElts)
+	checkColumnNotInPrimaryKey(b, col, cn)
+	b.Drop(col)
+	b.Drop(cn)
+	b.Drop(ct)
+	if _, _, cc := scpb.FindColumnComment(colElts); cc != nil {
+		b.Drop(cc)
+	}
+	handleDropColumnExpressions(b, colElts, behavior)
+	handleDropColumnIndexes(b, tn, col, behavior)
+	handleDropColumnComputedColumns(b, tn, cn, tbl, n, col, behavior)
+	handleDropColumnUniqueWithoutIndexConstraints(b, col, n)
+	handleDropColumnCheckConstraints(b, col, n)
+	handleDropColumnForeignKeyConstraintForwardReferences(b, col, n)
+	backrefs := undroppedBackrefs(b, col.TableID)
+	handleDropColumnViewBackReferences(b, backrefs, col, cn, behavior)
+	handleDropColumnForeignKeyConstraintBackReferences(b, cn, backrefs, col, n, behavior)
+	if !ct.IsVirtual {
+		handleDropColumnPrimaryIndexes(b, tbl, n, col)
+	}
+	assertAllColumnElementsAreDropped(colElts)
+}
+
+func checkColumnNotInPrimaryKey(b BuildCtx, col *scpb.Column, cn *scpb.ColumnName) {
+	publicTargets := b.QueryByID(col.TableID).Filter(publicTargetFilter)
+	_, _, pi := scpb.FindPrimaryIndex(publicTargets)
+	var ic *scpb.IndexColumn
+	scpb.ForEachIndexColumn(publicTargets, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.IndexColumn,
+	) {
+		if e.ColumnID == col.ColumnID &&
+			e.IndexID == pi.IndexID &&
+			e.Kind == scpb.IndexColumn_KEY {
+			ic = e
+		}
+	})
+	if ic != nil {
+		panic(sqlerrors.NewColumnReferencedByPrimaryKeyError(cn.Name))
+	}
+}
+
+func handleDropColumnComputedColumns(
+	b BuildCtx,
+	tn *tree.TableName,
+	cn *scpb.ColumnName,
+	tbl *scpb.Table,
+	n tree.NodeFormatter,
+	col *scpb.Column,
+	behavior tree.DropBehavior,
+) {
+	var toRemove catalog.TableColSet
+	allElts := b.QueryByID(col.TableID)
+	publicElts := allElts.Filter(publicTargetFilter)
+	scpb.ForEachColumnType(publicElts, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.ColumnType,
+	) {
+		// The below check is defensive given, at the time of writing, we already
+		// dropped the column type for the column in question.
+		if e.ColumnID == col.ColumnID ||
+			// We only care about references in the computed expression.
+			e.ComputeExpr == nil {
+			return
+		}
+		if descpb.ColumnIDs.Contains(e.ComputeExpr.ReferencedColumnIDs, col.ColumnID) {
+			toRemove.Add(e.ColumnID)
+		}
+	})
+	if !toRemove.Empty() && behavior != tree.DropCascade {
+		first, _ := toRemove.Next(0)
+		var computedColumnName *scpb.ColumnName
+		scpb.ForEachColumnName(publicElts, func(
+			_ scpb.Status, _ scpb.TargetStatus, e *scpb.ColumnName,
+		) {
+			if e.ColumnID == first {
+				computedColumnName = e
+			}
+		})
+		panic(sqlerrors.NewColumnReferencedByComputedColumnError(cn.Name, computedColumnName.Name))
+	}
+	toRemove.ForEach(func(computedColumnID descpb.ColumnID) {
+		elts := allElts.Filter(func(_ scpb.Status, _ scpb.TargetStatus, e scpb.Element) bool {
+			idI, _ := screl.Schema.GetAttribute(screl.ColumnID, e)
+			return idI != nil && idI.(catid.ColumnID) == computedColumnID
+		})
+		_, _, computedCol := scpb.FindColumn(elts)
+		dropColumn(b, tn, tbl, n, computedCol, elts, behavior)
+	})
+}
+
+func handleDropColumnPrimaryIndexes(
+	b BuildCtx, tbl *scpb.Table, n tree.NodeFormatter, col *scpb.Column,
+) {
+	// For now, disallow adding and dropping columns at the same time.
+	// In this case, we may need an intermediate index.
+	// TODO(ajwerner): Support mixing adding and dropping columns.
+	if addingAnyColumns := !b.QueryByID(tbl.TableID).
+		Filter(toPublicNotCurrentlyPublicFilter).
+		Filter(isColumnFilter).
+		IsEmpty(); addingAnyColumns {
+		panic(scerrors.NotImplementedErrorf(n, "DROP COLUMN after ADD COLUMN"))
+	}
+	existing, freshlyAdded := getPrimaryIndexes(b, tbl.TableID)
+	if freshlyAdded != nil {
+		handleDropColumnFreshlyAddedPrimaryIndex(b, tbl, freshlyAdded, col)
+	} else {
+		handleDropColumnCreateNewPrimaryIndex(b, tbl, existing, col)
+	}
+}
+
+func handleDropColumnCreateNewPrimaryIndex(
+	b BuildCtx, tbl *scpb.Table, existing *scpb.PrimaryIndex, col *scpb.Column,
+) *scpb.PrimaryIndex {
+	return createNewPrimaryIndex(b, tbl, existing, func(
+		b BuildCtx, newIndex *scpb.PrimaryIndex, existingColumns []*scpb.IndexColumn,
+	) (newColumns []*scpb.IndexColumn) {
+		var ic *scpb.IndexColumn
+		for _, c := range existingColumns {
+			if c.ColumnID == col.ColumnID {
+				ic = c
+				break
+			}
+		}
+		if ic == nil {
+			panic(errors.AssertionFailedf("failed to find column"))
+		}
+		if ic.Kind != scpb.IndexColumn_STORED {
+			panic(errors.AssertionFailedf("can only drop columns which are stored in the primary index, this one is %v ",
+				ic.Kind))
+		}
+		for _, ec := range existingColumns {
+			sameKind := ec.Kind == ic.Kind
+			if sameKind && ec.OrdinalInKind == ic.OrdinalInKind {
+				continue
+			}
+			cloned := protoutil.Clone(ec).(*scpb.IndexColumn)
+			if sameKind && ec.OrdinalInKind > ic.OrdinalInKind {
+				cloned.OrdinalInKind--
+			}
+			cloned.IndexID = newIndex.IndexID
+			newColumns = append(newColumns, cloned)
+			b.Add(cloned)
+		}
+		return newColumns
+	})
+}
+
+func handleDropColumnFreshlyAddedPrimaryIndex(
+	b BuildCtx, tbl *scpb.Table, freshlyAdded *scpb.PrimaryIndex, col *scpb.Column,
+) {
+	// We want to find the freshly added index and go ahead and remove this
+	// column from the stored set. That means going through the other
+	// index columns for this index and adjusting their ordinal appropriately.
+	var storedColumns, storedTempColumns []*scpb.IndexColumn
+	var tempIndex *scpb.TemporaryIndex
+	scpb.ForEachTemporaryIndex(b.QueryByID(tbl.TableID), func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.TemporaryIndex,
+	) {
+		if e.IndexID == freshlyAdded.TemporaryIndexID {
+			tempIndex = e
+		}
+	})
+	if tempIndex == nil {
+		panic(errors.AssertionFailedf("failed to find temp index %d", freshlyAdded.TemporaryIndexID))
+	}
+	scpb.ForEachIndexColumn(b.QueryByID(tbl.TableID).Filter(publicTargetFilter), func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.IndexColumn,
+	) {
+		if e.Kind != scpb.IndexColumn_STORED {
+			return
+		}
+		switch e.IndexID {
+		case tempIndex.IndexID:
+			storedTempColumns = append(storedTempColumns, e)
+		case freshlyAdded.IndexID:
+			storedColumns = append(storedColumns, e)
+		}
+	})
+	sort.Slice(storedColumns, func(i, j int) bool {
+		return storedColumns[i].OrdinalInKind < storedColumns[j].OrdinalInKind
+	})
+	sort.Slice(storedColumns, func(i, j int) bool {
+		return storedTempColumns[i].OrdinalInKind < storedTempColumns[j].OrdinalInKind
+	})
+	n := -1
+	for i, c := range storedColumns {
+		if c.ColumnID == col.ColumnID {
+			n = i
+			break
+		}
+	}
+	if n == -1 {
+		panic(errors.AssertionFailedf("failed to find column %d in index %d", col.ColumnID, freshlyAdded.TemporaryIndexID))
+	}
+	b.Drop(storedColumns[n])
+	b.Drop(storedTempColumns[n])
+	for i := n + 1; i < len(storedColumns); i++ {
+		storedColumns[i].OrdinalInKind--
+		b.Add(storedColumns[i])
+		storedTempColumns[i].OrdinalInKind--
+		b.Add(storedTempColumns[i])
+	}
+}
+
+func handleDropColumnUniqueWithoutIndexConstraints(
+	b BuildCtx, col *scpb.Column, n tree.NodeFormatter,
+) {
+	publicTargets := b.QueryByID(col.TableID).Filter(publicTargetFilter)
+	var constraints []*scpb.UniqueWithoutIndexConstraint
+	scpb.ForEachUniqueWithoutIndexConstraint(publicTargets, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.UniqueWithoutIndexConstraint,
+	) {
+		if descpb.ColumnIDs(e.ColumnIDs).Contains(col.ColumnID) {
+			constraints = append(constraints, e)
+		}
+	})
+	if len(constraints) == 0 {
+		return
+	}
+	// TODO(ajwerner): Support dropping UNIQUE WITHOUT INDEX constraints.
+	panic(errors.Wrap(scerrors.NotImplementedError(n),
+		"dropping of UNIQUE WITHOUT INDEX constraints not supported"))
+}
+
+func handleDropColumnCheckConstraints(b BuildCtx, col *scpb.Column, n tree.NodeFormatter) {
+	publicTargets := b.QueryByID(col.TableID).Filter(publicTargetFilter)
+	var constraints []*scpb.CheckConstraint
+	scpb.ForEachCheckConstraint(publicTargets, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.CheckConstraint,
+	) {
+		if descpb.ColumnIDs.Contains(e.ReferencedColumnIDs, col.ColumnID) {
+			constraints = append(constraints, e)
+		}
+	})
+	if len(constraints) == 0 {
+		return
+	}
+	// TODO(ajwerner): Support dropping CHECK constraints.
+	panic(errors.Wrap(scerrors.NotImplementedError(n),
+		"dropping of CHECK constraints not supported"))
+}
+
+func handleDropColumnForeignKeyConstraintForwardReferences(
+	b BuildCtx, col *scpb.Column, n tree.NodeFormatter,
+) {
+	publicTargets := b.QueryByID(col.TableID).Filter(publicTargetFilter)
+	var constraints []*scpb.ForeignKeyConstraint
+	scpb.ForEachForeignKeyConstraint(publicTargets, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.ForeignKeyConstraint,
+	) {
+		if descpb.ColumnIDs.Contains(e.ColumnIDs, col.ColumnID) {
+			constraints = append(constraints, e)
+		}
+	})
+	if len(constraints) == 0 {
+		return
+	}
+	// Here we will drop a constraint with or without cascade for outbound
+	// constraints.
+	// TODO(ajwerner): Support dropping FOREIGN KEY constraints.
+	panic(errors.Wrap(scerrors.NotImplementedError(n),
+		"dropping of FOREIGN KEY constraints not supported"))
+}
+
+func handleDropColumnForeignKeyConstraintBackReferences(
+	b BuildCtx,
+	cn *scpb.ColumnName,
+	backrefs ElementResultSet,
+	col *scpb.Column,
+	n tree.NodeFormatter,
+	behavior tree.DropBehavior,
+) {
+	publicTargets := b.QueryByID(col.TableID).Filter(publicTargetFilter)
+	var constraints []*scpb.ForeignKeyConstraint
+	scpb.ForEachForeignKeyConstraint(publicTargets, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.ForeignKeyConstraint,
+	) {
+		if descpb.ColumnIDs.Contains(e.ReferencedColumnIDs, col.ColumnID) {
+			constraints = append(constraints, e)
+		}
+	})
+	scpb.ForEachForeignKeyConstraint(backrefs, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.ForeignKeyConstraint,
+	) {
+		if descpb.ColumnIDs.Contains(e.ReferencedColumnIDs, col.ColumnID) {
+			constraints = append(constraints, e)
+		}
+	})
+	if len(constraints) == 0 {
+		return
+	}
+	if behavior != tree.DropCascade {
+		panic(pgerror.Newf(pgcode.DependentObjectsStillExist,
+			"cannot drop column %s because other objects depend on it", cn.Name))
+	}
+	// Here we will drop a constraint with or without cascade for outbound
+	// constraints.
+	// TODO(ajwerner): Support dropping FOREIGN KEY constraints.
+	panic(errors.Wrap(scerrors.NotImplementedError(n),
+		"dropping of FOREIGN KEY constraints not supported"))
+}
+
+func handleDropColumnExpressions(b BuildCtx, colElts ElementResultSet, behavior tree.DropBehavior) {
+	publicTargets := colElts.Filter(publicTargetFilter)
+	if _, _, de := scpb.FindColumnDefaultExpression(publicTargets); de != nil {
+		b.Drop(de)
+	}
+	if _, _, ue := scpb.FindColumnOnUpdateExpression(publicTargets); ue != nil {
+		b.Drop(ue)
+	}
+
+	// Find all the sequences owned by this column and drop them either restrict
+	// or cascade. Then, we'll need to check whether these sequences have any
+	// other backreferences which have not yet been dropped. Note that we don't
+	// need to wait for the other commands in this statement; postgres fails on
+	// something like:
+	//
+	//  create table t (i serial);
+	//  alter table t add column j default nextval('t_i_seq'::regclass);
+	//  alter table t drop column i, drop column j;
+	//  2BP01: cannot drop column i of table t because other objects depend on it
+	//
+	var undroppedBackrefsToCheck catalog.DescriptorIDSet
+	scpb.ForEachSequenceOwner(colElts, func(
+		_ scpb.Status, _ scpb.TargetStatus, so *scpb.SequenceOwner,
+	) {
+		if behavior == tree.DropCascade {
+			dropCascadeDescriptor(b, so.SequenceID)
+		} else {
+			dropRestrictDescriptor(b, so.SequenceID)
+			undroppedBackrefsToCheck.Add(so.SequenceID)
+			b.Drop(so)
+		}
+	})
+	// TODO(ajwerner): Track the undropped backrefs to populate a detail
+	// message like postgres does. For example:
+	//
+	//  create table t (i serial);
+	//  create table t2 (i int default nextval('t_i_seq'::regclass));
+	//  drop table t restrict;
+	//  ERROR:  cannot drop table t because other objects depend on it
+	//  DETAIL:  default value for column i of table t2 depends on sequence t_i_seq
+	//  HINT:  Use DROP ... CASCADE to drop the dependent objects too.
+	//
+	var hasUndroppedBackrefs bool
+	undroppedBackrefsToCheck.ForEach(func(seqID descpb.ID) {
+		udr := undroppedBackrefs(b, seqID)
+		if !udr.IsEmpty() {
+			hasUndroppedBackrefs = true
+		}
+	})
+	_, _, cn := scpb.FindColumnName(colElts)
+	if hasUndroppedBackrefs {
+		panic(pgerror.Newf(pgcode.DependentObjectsStillExist,
+			"cannot drop column %s because other objects depend on it", cn.Name))
+	}
+}
+
+func handleDropColumnViewBackReferences(
+	b BuildCtx,
+	backrefs ElementResultSet,
+	col *scpb.Column,
+	cn *scpb.ColumnName,
+	dropBehavior tree.DropBehavior,
+) {
+	var views []*scpb.View
+	scpb.ForEachView(backrefs, func(_ scpb.Status, _ scpb.TargetStatus, e *scpb.View) {
+		for _, ref := range e.ForwardReferences {
+			if ref.ToID == col.TableID &&
+				catalog.MakeTableColSet(ref.ColumnIDs...).Contains(col.ColumnID) {
+				views = append(views, e)
+			}
+		}
+	})
+	if len(views) == 0 {
+		return
+	}
+	if dropBehavior == tree.DropCascade {
+		for _, v := range views {
+			dropCascadeDescriptor(b, v.ViewID)
+		}
+		return
+	}
+	depView := views[0]
+	_, _, ns := scpb.FindNamespace(b.QueryByID(col.TableID))
+	_, _, nsDep := scpb.FindNamespace(b.QueryByID(depView.ViewID))
+	if nsDep.DatabaseID != ns.DatabaseID || nsDep.SchemaID != ns.SchemaID {
+		panic(errors.WithHintf(sqlerrors.NewDependentObjectErrorf(
+			"cannot drop column %q because view %q depends on it",
+			cn.Name, qualifiedName(b, depView.ViewID)),
+			"you can drop %s instead.", nsDep.Name))
+	}
+	panic(sqlerrors.NewDependentObjectErrorf(
+		"cannot drop column %q because view %q depends on it",
+		cn.Name, nsDep.Name))
+}
+
+func handleDropColumnIndexes(
+	b BuildCtx, tn *tree.TableName, col *scpb.Column, dropBehavior tree.DropBehavior,
+) {
+	tableElts := b.QueryByID(col.TableID).Filter(publicTargetFilter)
+	var indexIDs catid.IndexSet
+	scpb.ForEachIndexColumn(tableElts, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.IndexColumn,
+	) {
+		if e.ColumnID == col.ColumnID {
+			indexIDs.Add(e.IndexID)
+		}
+	})
+	scpb.ForEachSecondaryIndexPartial(tableElts, func(
+		current scpb.Status, target scpb.TargetStatus, e *scpb.SecondaryIndexPartial,
+	) {
+		if descpb.ColumnIDs.Contains(e.ReferencedColumnIDs, col.ColumnID) {
+			indexIDs.Add(e.IndexID)
+		}
+	})
+	var secondaryIndexIDs catid.IndexSet
+	var indexes []*scpb.SecondaryIndex
+	var indexNames []*scpb.IndexName
+	scpb.ForEachSecondaryIndex(tableElts, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.SecondaryIndex,
+	) {
+		if indexIDs.Contains(e.IndexID) {
+			secondaryIndexIDs.Add(e.IndexID)
+			indexes = append(indexes, e)
+		}
+	})
+	scpb.ForEachIndexName(tableElts, func(
+		_ scpb.Status, _ scpb.TargetStatus, e *scpb.IndexName,
+	) {
+		if secondaryIndexIDs.Contains(e.IndexID) {
+			indexNames = append(indexNames, e)
+		}
+	})
+	if len(indexNames) != len(indexes) {
+		panic(errors.AssertionFailedf("indexes %v does not match indexNames %v",
+			indexes, indexNames))
+	}
+	sort.Slice(indexes, func(i, j int) bool {
+		return indexes[i].IndexID < indexes[j].IndexID
+	})
+	sort.Slice(indexNames, func(i, j int) bool {
+		return indexNames[i].IndexID < indexNames[j].IndexID
+	})
+	for i, idx := range indexes {
+		name := tree.TableIndexName{
+			Table: *tn,
+			Index: tree.UnrestrictedName(indexNames[i].Name),
+		}
+		indexElts := tableElts.Filter(func(
+			current scpb.Status, target scpb.TargetStatus, e scpb.Element,
+		) bool {
+			idI, _ := screl.Schema.GetAttribute(screl.IndexID, e)
+			return idI != nil && idI.(catid.IndexID) == idx.IndexID
+		})
+		dropSecondaryIndex(b, &name, dropBehavior, idx, indexElts)
+	}
+}
+
+func assertAllColumnElementsAreDropped(colElts ElementResultSet) {
+	if stillPublic := colElts.Filter(publicTargetFilter); !stillPublic.IsEmpty() {
+		var elements []scpb.Element
+		stillPublic.ForEachElementStatus(func(_ scpb.Status, _ scpb.TargetStatus, e scpb.Element) {
+			elements = append(elements, e)
+		})
+		panic(errors.AssertionFailedf("failed to drop all of the relevant elements: %v", elements))
+	}
+}
diff --git a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/create_index.go b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/create_index.go
index eabf1175064d..b1187d8ac1b2 100644
--- a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/create_index.go
+++ b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/create_index.go
@@ -234,7 +234,7 @@ func CreateIndex(b BuildCtx, n *tree.CreateIndex) {
 		if err != nil {
 			panic(err)
 		}
-		shardColName := maybeCreateAndAddShardCol(b, int(buckets), relation.(*scpb.Table), keyColNames)
+		shardColName := maybeCreateAndAddShardCol(b, int(buckets), relation.(*scpb.Table), keyColNames, n)
 		index.Sharding = &catpb.ShardedDescriptor{
 			IsSharded:    true,
 			Name:         shardColName,
@@ -312,7 +312,7 @@ func nextRelationIndexID(b BuildCtx, relation scpb.Element) catid.IndexID {
 // `desc`, if one doesn't already exist for the given index column set and number of shard
 // buckets.
 func maybeCreateAndAddShardCol(
-	b BuildCtx, shardBuckets int, tbl *scpb.Table, colNames []string,
+	b BuildCtx, shardBuckets int, tbl *scpb.Table, colNames []string, n tree.NodeFormatter,
 ) (shardColName string) {
 	shardColName = tabledesc.GetShardColumnName(colNames, int32(shardBuckets))
 	elts := b.QueryByID(tbl.TableID)
@@ -362,7 +362,7 @@ func maybeCreateAndAddShardCol(
 			ComputeExpr: b.WrapExpression(tbl.TableID, parsedExpr),
 		},
 	}
-	addColumn(b, spec)
+	addColumn(b, spec, n)
 	return shardColName
 }
 
diff --git a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/drop_index.go b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/drop_index.go
index f0363479f874..76a10b7d908a 100644
--- a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/drop_index.go
+++ b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/drop_index.go
@@ -141,7 +141,7 @@ func dropSecondaryIndex(
 	// In this case, if we were to drop 'ui' and no other unique constraint can be
 	// found to replace 'uc' (to continue to serve 'fk'), we will require CASCADE
 	//and drop 'fk' as well.
-	maybeDropDependentFKConstraints(b, sie, index.String(), dropBehavior)
+	maybeDropDependentFKConstraints(b, sie, index, dropBehavior)
 
 	// If shard index, also drop the shard column and all check constraints that
 	// uses this shard column if no other index uses the shard column.
@@ -149,7 +149,7 @@ func dropSecondaryIndex(
 
 	// If expression index, also drop the expression column if no other index is
 	// using the expression column.
-	dropAdditionallyForExpressionIndex(b, sie, index.String())
+	dropAdditionallyForExpressionIndex(b, sie)
 
 	// Finally, drop the index's resolved elements.
 	toBeDroppedIndexElms.ForEachElementStatus(func(current scpb.Status, target scpb.TargetStatus, e scpb.Element) {
@@ -204,7 +204,7 @@ func maybeDropDependentViews(
 func maybeDropDependentFKConstraints(
 	b BuildCtx,
 	toBeDroppedIndex *scpb.SecondaryIndex,
-	toBeDroppedIndexName string,
+	toBeDroppedIndexName *tree.TableIndexName,
 	dropBehavior tree.DropBehavior,
 ) {
 	scpb.ForEachForeignKeyConstraint(b.BackReferences(toBeDroppedIndex.TableID), func(
@@ -227,8 +227,8 @@ func maybeDropDependentFKConstraints(
 		// references), so, we will need to remove the dependent FK
 		// constraint as well.
 		if dropBehavior != tree.DropCascade {
-			_, _, ns := scpb.FindNamespace(b.QueryByID(toBeDroppedIndex.TableID))
-			panic(fmt.Errorf("%q is referenced by foreign key from table %q", toBeDroppedIndexName, ns.Name))
+			_, _, ns := scpb.FindNamespace(b.QueryByID(e.TableID))
+			panic(fmt.Errorf("%q is referenced by foreign key from table %q", toBeDroppedIndexName.Index, ns.Name))
 		}
 
 		// TODO (xiang): enable resolving and dropping FK constraint elements.
@@ -308,9 +308,7 @@ func maybeDropAdditionallyForShardedIndex(
 // dropAdditionallyForExpressionIndex attempts to drop the additional
 // expression column if the to-be-dropped index is an expression index
 // and no other index uses this expression column.
-func dropAdditionallyForExpressionIndex(
-	b BuildCtx, toBeDroppedIndex *scpb.SecondaryIndex, toBeDroppedIndexName string,
-) {
+func dropAdditionallyForExpressionIndex(b BuildCtx, toBeDroppedIndex *scpb.SecondaryIndex) {
 	keyColumnIDs, _, _ := getSortedColumnIDsInIndex(b, toBeDroppedIndex.TableID, toBeDroppedIndex.IndexID)
 	scpb.ForEachColumn(b.QueryByID(toBeDroppedIndex.TableID), func(
 		current scpb.Status, target scpb.TargetStatus, ce *scpb.Column,
diff --git a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/helpers.go b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/helpers.go
index 1e5694069a83..db4437add65c 100644
--- a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/helpers.go
+++ b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/helpers.go
@@ -304,15 +304,32 @@ func getSortedColumnIDsInIndex(
 	return keyColumnIDs, keySuffixColumnIDs, storingColumnIDs
 }
 
+func toPublicNotCurrentlyPublicFilter(
+	status scpb.Status, target scpb.TargetStatus, _ scpb.Element,
+) bool {
+	return status != scpb.Status_PUBLIC && target == scpb.ToPublic
+}
+
+func isColumnFilter(_ scpb.Status, _ scpb.TargetStatus, e scpb.Element) bool {
+	_, isColumn := e.(*scpb.Column)
+	return isColumn
+}
+
 func publicTargetFilter(_ scpb.Status, target scpb.TargetStatus, _ scpb.Element) bool {
 	return target == scpb.ToPublic
 }
 
-func statusAbsentOrBackfillOnly(status scpb.Status, _ scpb.TargetStatus, _ scpb.Element) bool {
+func absentTargetFilter(_ scpb.Status, target scpb.TargetStatus, _ scpb.Element) bool {
+	return target == scpb.ToAbsent
+}
+
+func statusAbsentOrBackfillOnlyFilter(
+	status scpb.Status, _ scpb.TargetStatus, _ scpb.Element,
+) bool {
 	return status == scpb.Status_ABSENT || status == scpb.Status_BACKFILL_ONLY
 }
 
-func statusPublic(status scpb.Status, _ scpb.TargetStatus, _ scpb.Element) bool {
+func statusPublicFilter(status scpb.Status, _ scpb.TargetStatus, _ scpb.Element) bool {
 	return status == scpb.Status_PUBLIC
 }
 
@@ -331,8 +348,8 @@ func getPrimaryIndexes(
 	allTargets := b.QueryByID(tableID)
 	_, _, freshlyAdded = scpb.FindPrimaryIndex(allTargets.
 		Filter(publicTargetFilter).
-		Filter(statusAbsentOrBackfillOnly))
-	_, _, existing = scpb.FindPrimaryIndex(allTargets.Filter(statusPublic))
+		Filter(statusAbsentOrBackfillOnlyFilter))
+	_, _, existing = scpb.FindPrimaryIndex(allTargets.Filter(statusPublicFilter))
 	if existing == nil {
 		// TODO(postamar): can this even be possible?
 		panic(pgerror.Newf(pgcode.NoPrimaryKey, "missing active primary key"))
diff --git a/pkg/sql/schemachanger/scbuild/testdata/alter_table_drop_column b/pkg/sql/schemachanger/scbuild/testdata/alter_table_drop_column
new file mode 100644
index 000000000000..03d1470d3d9c
--- /dev/null
+++ b/pkg/sql/schemachanger/scbuild/testdata/alter_table_drop_column
@@ -0,0 +1,177 @@
+setup
+SET serial_normalization = sql_sequence;
+CREATE TABLE defaultdb.t (
+    i INT8 PRIMARY KEY,
+    j INT8 DEFAULT 42 NOT NULL,
+    k INT8 NOT NULL,
+    l SERIAL,
+    INDEX (j),
+    INDEX (j, k)
+);
+----
+
+build
+ALTER TABLE defaultdb.t DROP COLUMN j
+----
+- [[Column:{DescID: 104, ColumnID: 2}, ABSENT], PUBLIC]
+  {columnId: 2, pgAttributeNum: 2, tableId: 104}
+- [[ColumnName:{DescID: 104, Name: j, ColumnID: 2}, ABSENT], PUBLIC]
+  {columnId: 2, name: j, tableId: 104}
+- [[ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}, ABSENT], PUBLIC]
+  {columnId: 2, tableId: 104, type: {family: IntFamily, oid: 20, width: 64}}
+- [[ColumnDefaultExpression:{DescID: 104, ColumnID: 2}, ABSENT], PUBLIC]
+  {columnId: 2, expr: '42:::INT8', tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 1, indexId: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 2, indexId: 1, kind: STORED, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 3, indexId: 1, kind: STORED, ordinalInKind: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 4, indexId: 1, kind: STORED, ordinalInKind: 2, tableId: 104}
+- [[PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}, ABSENT], PUBLIC]
+  {constraintId: 1, indexId: 1, isUnique: true, tableId: 104}
+- [[IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}, ABSENT], PUBLIC]
+  {indexId: 1, name: t_pkey, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 2}, ABSENT], PUBLIC]
+  {columnId: 2, indexId: 2, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}, ABSENT], PUBLIC]
+  {columnId: 1, indexId: 2, kind: KEY_SUFFIX, tableId: 104}
+- [[SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}, ABSENT], PUBLIC]
+  {indexId: 2, tableId: 104}
+- [[IndexName:{DescID: 104, Name: t_j_idx, IndexID: 2}, ABSENT], PUBLIC]
+  {indexId: 2, name: t_j_idx, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 3}, ABSENT], PUBLIC]
+  {columnId: 2, indexId: 3, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}, ABSENT], PUBLIC]
+  {columnId: 3, indexId: 3, ordinalInKind: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}, ABSENT], PUBLIC]
+  {columnId: 1, indexId: 3, kind: KEY_SUFFIX, tableId: 104}
+- [[SecondaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 0}, ABSENT], PUBLIC]
+  {indexId: 3, tableId: 104}
+- [[IndexName:{DescID: 104, Name: t_j_k_idx, IndexID: 3}, ABSENT], PUBLIC]
+  {indexId: 3, name: t_j_k_idx, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}, PUBLIC], ABSENT]
+  {columnId: 1, indexId: 4, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}, PUBLIC], ABSENT]
+  {columnId: 3, indexId: 4, kind: STORED, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 4}, PUBLIC], ABSENT]
+  {columnId: 4, indexId: 4, kind: STORED, ordinalInKind: 1, tableId: 104}
+- [[PrimaryIndex:{DescID: 104, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}, PUBLIC], ABSENT]
+  {constraintId: 1, indexId: 4, isUnique: true, sourceIndexId: 1, tableId: 104, temporaryIndexId: 5}
+- [[IndexName:{DescID: 104, Name: t_pkey, IndexID: 4}, PUBLIC], ABSENT]
+  {indexId: 4, name: t_pkey, tableId: 104}
+- [[TemporaryIndex:{DescID: 104, IndexID: 5, SourceIndexID: 1}, TRANSIENT_ABSENT], ABSENT]
+  {constraintId: 1, indexId: 5, isUnique: true, sourceIndexId: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 5}, PUBLIC], ABSENT]
+  {columnId: 1, indexId: 5, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 5}, PUBLIC], ABSENT]
+  {columnId: 3, indexId: 5, kind: STORED, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 5}, PUBLIC], ABSENT]
+  {columnId: 4, indexId: 5, kind: STORED, ordinalInKind: 1, tableId: 104}
+
+build
+ALTER TABLE defaultdb.t DROP COLUMN k
+----
+- [[Column:{DescID: 104, ColumnID: 3}, ABSENT], PUBLIC]
+  {columnId: 3, pgAttributeNum: 3, tableId: 104}
+- [[ColumnName:{DescID: 104, Name: k, ColumnID: 3}, ABSENT], PUBLIC]
+  {columnId: 3, name: k, tableId: 104}
+- [[ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}, ABSENT], PUBLIC]
+  {columnId: 3, tableId: 104, type: {family: IntFamily, oid: 20, width: 64}}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 1, indexId: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 2, indexId: 1, kind: STORED, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 3, indexId: 1, kind: STORED, ordinalInKind: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 4, indexId: 1, kind: STORED, ordinalInKind: 2, tableId: 104}
+- [[PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}, ABSENT], PUBLIC]
+  {constraintId: 1, indexId: 1, isUnique: true, tableId: 104}
+- [[IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}, ABSENT], PUBLIC]
+  {indexId: 1, name: t_pkey, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 3}, ABSENT], PUBLIC]
+  {columnId: 2, indexId: 3, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}, ABSENT], PUBLIC]
+  {columnId: 3, indexId: 3, ordinalInKind: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}, ABSENT], PUBLIC]
+  {columnId: 1, indexId: 3, kind: KEY_SUFFIX, tableId: 104}
+- [[SecondaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 0}, ABSENT], PUBLIC]
+  {indexId: 3, tableId: 104}
+- [[IndexName:{DescID: 104, Name: t_j_k_idx, IndexID: 3}, ABSENT], PUBLIC]
+  {indexId: 3, name: t_j_k_idx, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}, PUBLIC], ABSENT]
+  {columnId: 1, indexId: 4, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 4}, PUBLIC], ABSENT]
+  {columnId: 2, indexId: 4, kind: STORED, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 4}, PUBLIC], ABSENT]
+  {columnId: 4, indexId: 4, kind: STORED, ordinalInKind: 1, tableId: 104}
+- [[PrimaryIndex:{DescID: 104, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}, PUBLIC], ABSENT]
+  {constraintId: 1, indexId: 4, isUnique: true, sourceIndexId: 1, tableId: 104, temporaryIndexId: 5}
+- [[IndexName:{DescID: 104, Name: t_pkey, IndexID: 4}, PUBLIC], ABSENT]
+  {indexId: 4, name: t_pkey, tableId: 104}
+- [[TemporaryIndex:{DescID: 104, IndexID: 5, SourceIndexID: 1}, TRANSIENT_ABSENT], ABSENT]
+  {constraintId: 1, indexId: 5, isUnique: true, sourceIndexId: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 5}, PUBLIC], ABSENT]
+  {columnId: 1, indexId: 5, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 5}, PUBLIC], ABSENT]
+  {columnId: 2, indexId: 5, kind: STORED, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 5}, PUBLIC], ABSENT]
+  {columnId: 4, indexId: 5, kind: STORED, ordinalInKind: 1, tableId: 104}
+
+build
+ALTER TABLE defaultdb.t DROP COLUMN l
+----
+- [[Column:{DescID: 104, ColumnID: 4}, ABSENT], PUBLIC]
+  {columnId: 4, pgAttributeNum: 4, tableId: 104}
+- [[ColumnName:{DescID: 104, Name: l, ColumnID: 4}, ABSENT], PUBLIC]
+  {columnId: 4, name: l, tableId: 104}
+- [[ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}, ABSENT], PUBLIC]
+  {columnId: 4, tableId: 104, type: {family: IntFamily, oid: 20, width: 64}}
+- [[ColumnDefaultExpression:{DescID: 104, ColumnID: 4}, ABSENT], PUBLIC]
+  {columnId: 4, expr: 'nextval(105:::REGCLASS)', tableId: 104, usesSequenceIds: [105]}
+- [[SequenceOwner:{DescID: 104, ColumnID: 4, ReferencedDescID: 105}, ABSENT], PUBLIC]
+  {columnId: 4, sequenceId: 105, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 1, indexId: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 2, indexId: 1, kind: STORED, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 3, indexId: 1, kind: STORED, ordinalInKind: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 1}, ABSENT], PUBLIC]
+  {columnId: 4, indexId: 1, kind: STORED, ordinalInKind: 2, tableId: 104}
+- [[PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}, ABSENT], PUBLIC]
+  {constraintId: 1, indexId: 1, isUnique: true, tableId: 104}
+- [[IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}, ABSENT], PUBLIC]
+  {indexId: 1, name: t_pkey, tableId: 104}
+- [[Namespace:{DescID: 105, Name: t_l_seq, ReferencedDescID: 100}, ABSENT], PUBLIC]
+  {databaseId: 100, descriptorId: 105, name: t_l_seq, schemaId: 101}
+- [[Owner:{DescID: 105}, ABSENT], PUBLIC]
+  {descriptorId: 105, owner: root}
+- [[UserPrivileges:{DescID: 105, Name: admin}, ABSENT], PUBLIC]
+  {descriptorId: 105, privileges: 2, userName: admin}
+- [[UserPrivileges:{DescID: 105, Name: root}, ABSENT], PUBLIC]
+  {descriptorId: 105, privileges: 2, userName: root}
+- [[Sequence:{DescID: 105}, ABSENT], PUBLIC]
+  {sequenceId: 105}
+- [[ObjectParent:{DescID: 105, ReferencedDescID: 101}, ABSENT], PUBLIC]
+  {objectId: 105, parentSchemaId: 101}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}, PUBLIC], ABSENT]
+  {columnId: 1, indexId: 4, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 4}, PUBLIC], ABSENT]
+  {columnId: 2, indexId: 4, kind: STORED, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}, PUBLIC], ABSENT]
+  {columnId: 3, indexId: 4, kind: STORED, ordinalInKind: 1, tableId: 104}
+- [[PrimaryIndex:{DescID: 104, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}, PUBLIC], ABSENT]
+  {constraintId: 1, indexId: 4, isUnique: true, sourceIndexId: 1, tableId: 104, temporaryIndexId: 5}
+- [[IndexName:{DescID: 104, Name: t_pkey, IndexID: 4}, PUBLIC], ABSENT]
+  {indexId: 4, name: t_pkey, tableId: 104}
+- [[TemporaryIndex:{DescID: 104, IndexID: 5, SourceIndexID: 1}, TRANSIENT_ABSENT], ABSENT]
+  {constraintId: 1, indexId: 5, isUnique: true, sourceIndexId: 1, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 5}, PUBLIC], ABSENT]
+  {columnId: 1, indexId: 5, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 5}, PUBLIC], ABSENT]
+  {columnId: 2, indexId: 5, kind: STORED, tableId: 104}
+- [[IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 5}, PUBLIC], ABSENT]
+  {columnId: 3, indexId: 5, kind: STORED, ordinalInKind: 1, tableId: 104}
diff --git a/pkg/sql/schemachanger/scbuild/testdata/unimplemented_alter_table b/pkg/sql/schemachanger/scbuild/testdata/unimplemented_alter_table
index 48ff65ea7ba0..2cd33ad8f7c5 100644
--- a/pkg/sql/schemachanger/scbuild/testdata/unimplemented_alter_table
+++ b/pkg/sql/schemachanger/scbuild/testdata/unimplemented_alter_table
@@ -1,5 +1,15 @@
 setup
-CREATE TABLE defaultdb.foo (i INT PRIMARY KEY)
+SET experimental_enable_unique_without_index_constraints = true;
+CREATE TABLE defaultdb.foo (
+    i INT8 PRIMARY KEY,
+    -- j gets added by the test
+    k INT8 CHECK (k > 10),
+    l INT8 UNIQUE,
+    m INT8 REFERENCES foo (l),
+    n UUID,
+    UNIQUE WITHOUT INDEX (n),
+    o INT -- this column can be dropped
+);
 ----
 
 unimplemented
@@ -27,7 +37,27 @@ ALTER TABLE defaultdb.foo ALTER PRIMARY KEY USING COLUMNS (i)
 ----
 
 unimplemented
-ALTER TABLE defaultdb.foo DROP COLUMN i
+ALTER TABLE defaultdb.foo DROP COLUMN k
+----
+
+unimplemented
+ALTER TABLE defaultdb.foo DROP COLUMN l CASCADE;
+----
+
+unimplemented
+ALTER TABLE defaultdb.foo DROP COLUMN m
+----
+
+unimplemented
+ALTER TABLE defaultdb.foo DROP COLUMN n
+----
+
+unimplemented
+ALTER TABLE defaultdb.foo DROP COLUMN o, ADD COLUMN p INT
+----
+
+unimplemented
+ALTER TABLE defaultdb.foo ADD COLUMN p INT, DROP COLUMN o
 ----
 
 unimplemented
diff --git a/pkg/sql/schemachanger/scplan/internal/scstage/build.go b/pkg/sql/schemachanger/scplan/internal/scstage/build.go
index 99dde6fc0e23..83934907f19a 100644
--- a/pkg/sql/schemachanger/scplan/internal/scstage/build.go
+++ b/pkg/sql/schemachanger/scplan/internal/scstage/build.go
@@ -12,6 +12,7 @@ package scstage
 
 import (
 	"fmt"
+	"sort"
 
 	"github.com/cockroachdb/cockroach/pkg/jobs/jobspb"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog"
@@ -638,20 +639,32 @@ func (bc buildContext) makeDescriptorStates(cur, next *Stage) map[descpb.ID]*scp
 			Revertible:    isRevertible(next),
 		}
 	})
+	mkStmt := func(rank uint32) scpb.DescriptorState_Statement {
+		return scpb.DescriptorState_Statement{
+			Statement:     bc.targetState.Statements[rank],
+			StatementRank: rank,
+		}
+	}
 	// Populate the descriptor states.
-	noteRelevantStatement := func(state *scpb.DescriptorState, stmtRank uint32) {
-		for i := range state.RelevantStatements {
-			stmt := &state.RelevantStatements[i]
-			if stmt.StatementRank != stmtRank {
-				continue
-			}
-			return
+	addToRelevantStatements := func(
+		srs []scpb.DescriptorState_Statement, stmtRank uint32,
+	) []scpb.DescriptorState_Statement {
+		n := len(srs)
+		if i := sort.Search(n, func(i int) bool {
+			return srs[i].StatementRank >= stmtRank
+		}); i == n {
+			srs = append(srs, mkStmt(stmtRank))
+		} else if srs[i].StatementRank != stmtRank {
+			srs = append(srs, scpb.DescriptorState_Statement{})
+			copy(srs[i+1:], srs[i:])
+			srs[i] = mkStmt(stmtRank)
 		}
-		state.RelevantStatements = append(state.RelevantStatements,
-			scpb.DescriptorState_Statement{
-				Statement:     bc.targetState.Statements[stmtRank],
-				StatementRank: stmtRank,
-			})
+		return srs
+	}
+	noteRelevantStatement := func(state *scpb.DescriptorState, stmtRank uint32) {
+		state.RelevantStatements = addToRelevantStatements(
+			state.RelevantStatements, stmtRank,
+		)
 	}
 	for i, t := range bc.targetState.Targets {
 		descID := screl.GetDescID(t.Element())
diff --git a/pkg/sql/schemachanger/sctest/cumulative.go b/pkg/sql/schemachanger/sctest/cumulative.go
index 9f2814b0760c..c5ad82f92843 100644
--- a/pkg/sql/schemachanger/sctest/cumulative.go
+++ b/pkg/sql/schemachanger/sctest/cumulative.go
@@ -88,9 +88,7 @@ func Rollback(t *testing.T, dir string, newCluster NewClusterFunc) {
 		processPlanInPhase(
 			t, newCluster, setup, stmts, scop.PostCommitPhase,
 			func(p scplan.Plan) { n = len(p.StagesForCurrentPhase()) },
-			func(db *gosql.DB) {
-
-			},
+			func(db *gosql.DB) {},
 		)
 		return n
 	}
@@ -517,7 +515,7 @@ SELECT name
 func processPlanInPhase(
 	t *testing.T,
 	newCluster NewClusterFunc,
-	setup, stmt []parser.Statement,
+	setup, stmts []parser.Statement,
 	phaseToProcess scop.Phase,
 	processFunc func(p scplan.Plan),
 	after func(db *gosql.DB),
@@ -533,7 +531,7 @@ func processPlanInPhase(
 	})
 	defer cleanup()
 	require.NoError(t, executeSchemaChangeTxn(
-		context.Background(), t, setup, stmt, db, nil, nil, nil,
+		context.Background(), t, setup, stmts, db, nil, nil, nil,
 	))
 	if after != nil {
 		after(db)
diff --git a/pkg/sql/schemachanger/testdata/end_to_end/drop_column_basic b/pkg/sql/schemachanger/testdata/end_to_end/drop_column_basic
new file mode 100644
index 000000000000..26ce5731560b
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/end_to_end/drop_column_basic
@@ -0,0 +1,517 @@
+setup
+create table t (i int primary key, j int)
+----
+...
++object {100 101 t} -> 104
+
+test
+alter table t drop column j
+----
+begin transaction #1
+# begin StatementPhase
+checking for feature: ALTER TABLE
+increment telemetry for sql.schema.alter_table
+increment telemetry for sql.schema.alter_table.drop_column
+## StatementPhase stage 1 of 1 with 7 MutationType ops
+upsert descriptor #104
+  ...
+         oid: 20
+         width: 64
+  -  - id: 2
+  -    name: j
+  -    nullable: true
+  -    type:
+  -      family: IntFamily
+  -      oid: 20
+  -      width: 64
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  ...
+       columnNames:
+       - i
+  -    - j
+  +    - crdb_internal_column_2_name_placeholder
+       defaultColumnId: 2
+       name: primary
+     formatVersion: 3
+     id: 104
+  -  modificationTime:
+  -    wallTime: "1640995200000000000"
+  +  modificationTime: {}
+  +  mutations:
+  +  - column:
+  +      id: 2
+  +      name: crdb_internal_column_2_name_placeholder
+  +      nullable: true
+  +      type:
+  +        family: IntFamily
+  +        oid: 20
+  +        width: 64
+  +    direction: DROP
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 2
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 2
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - i
+  +      name: crdb_internal_index_2_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnNames: []
+  +      unique: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: BACKFILLING
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 3
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 3
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - i
+  +      name: crdb_internal_index_3_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnNames: []
+  +      unique: true
+  +      useDeletePreservingEncoding: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 3
+  -  nextConstraintId: 2
+  +  nextConstraintId: 4
+     nextFamilyId: 1
+  -  nextIndexId: 2
+  +  nextIndexId: 4
+     nextMutationId: 1
+     parentId: 100
+  ...
+       - 2
+       storeColumnNames:
+  -    - j
+  +    - crdb_internal_column_2_name_placeholder
+       unique: true
+       version: 4
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "1"
+  +  version: "2"
+write *eventpb.AlterTable to event log for descriptor #104: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+# end StatementPhase
+# begin PreCommitPhase
+## PreCommitPhase stage 1 of 1 with 2 MutationType ops
+upsert descriptor #104
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  +  declarativeSchemaChangerState:
+  +    authorization:
+  +      userName: root
+  +    currentStatuses: <redacted>
+  +    jobId: "1"
+  +    relevantStatements:
+  +    - statement:
+  +        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+  +        statement: ALTER TABLE t DROP COLUMN j
+  +        statementTag: ALTER TABLE
+  +    revertible: true
+  +    targetRanks: <redacted>
+  +    targets: <redacted>
+     families:
+     - columnIds:
+  ...
+     formatVersion: 3
+     id: 104
+  -  modificationTime: {}
+  +  modificationTime:
+  +    wallTime: "1640995200000000001"
+     mutations:
+     - column:
+  ...
+create job #1 (non-cancelable: false): "ALTER TABLE defaultdb.public.t DROP COLUMN j"
+  descriptor IDs: [104]
+# end PreCommitPhase
+commit transaction #1
+notified job registry to adopt jobs: [1]
+# begin PostCommitPhase
+begin transaction #2
+commit transaction #2
+begin transaction #3
+## PostCommitPhase stage 1 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     formatVersion: 3
+     id: 104
+  -  modificationTime:
+  -    wallTime: "1640995200000000001"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: DELETE_AND_WRITE_ONLY
+     name: t
+     nextColumnId: 3
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "2"
+  +  version: "3"
+update progress of schema change job #1: "PostCommitPhase stage 2 of 7 with 1 BackfillType op pending"
+commit transaction #3
+begin transaction #4
+## PostCommitPhase stage 2 of 7 with 1 BackfillType op
+backfill indexes [2] from index #1 in table #104
+commit transaction #4
+begin transaction #5
+## PostCommitPhase stage 3 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     formatVersion: 3
+     id: 104
+  -  modificationTime:
+  -    wallTime: "1640995200000000003"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: BACKFILLING
+  +    state: DELETE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "3"
+  +  version: "4"
+update progress of schema change job #1: "PostCommitPhase stage 4 of 7 with 1 MutationType op pending"
+commit transaction #5
+begin transaction #6
+## PostCommitPhase stage 4 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     formatVersion: 3
+     id: 104
+  -  modificationTime:
+  -    wallTime: "1640995200000000005"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: MERGING
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "4"
+  +  version: "5"
+update progress of schema change job #1: "PostCommitPhase stage 5 of 7 with 1 BackfillType op pending"
+commit transaction #6
+begin transaction #7
+## PostCommitPhase stage 5 of 7 with 1 BackfillType op
+merge temporary indexes [3] into backfilled indexes [2] in table #104
+commit transaction #7
+begin transaction #8
+## PostCommitPhase stage 6 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     formatVersion: 3
+     id: 104
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "5"
+  +  version: "6"
+update progress of schema change job #1: "PostCommitPhase stage 7 of 7 with 1 ValidationType op pending"
+commit transaction #8
+begin transaction #9
+## PostCommitPhase stage 7 of 7 with 1 ValidationType op
+validate forward indexes [2] in table #104
+commit transaction #9
+begin transaction #10
+## PostCommitNonRevertiblePhase stage 1 of 3 with 10 MutationType ops
+upsert descriptor #104
+  ...
+           statement: ALTER TABLE t DROP COLUMN j
+           statementTag: ALTER TABLE
+  -    revertible: true
+       targetRanks: <redacted>
+       targets: <redacted>
+  ...
+     formatVersion: 3
+     id: 104
+  -  modificationTime:
+  -    wallTime: "1640995200000000008"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+       direction: DROP
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 2
+  +      constraintId: 3
+         createdExplicitly: true
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 2
+  +      id: 3
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - i
+  -      name: crdb_internal_index_2_name_placeholder
+  +      name: crdb_internal_index_3_name_placeholder
+         partitioning: {}
+         sharded: {}
+         storeColumnNames: []
+         unique: true
+  +      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 3
+  -      createdExplicitly: true
+  +      constraintId: 1
+  +      createdAtNanos: "1640995200000000000"
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 3
+  +      id: 1
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - i
+  -      name: crdb_internal_index_3_name_placeholder
+  +      name: crdb_internal_index_1_name_placeholder
+         partitioning: {}
+         sharded: {}
+  -      storeColumnNames: []
+  +      storeColumnIds:
+  +      - 2
+  +      storeColumnNames:
+  +      - crdb_internal_column_2_name_placeholder
+         unique: true
+  -      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 1
+  ...
+     parentId: 100
+     primaryIndex:
+  -    constraintId: 1
+  -    createdAtNanos: "1640995200000000000"
+  +    constraintId: 2
+  +    createdExplicitly: true
+       encodingType: 1
+       foreignKey: {}
+       geoConfig: {}
+  -    id: 1
+  +    id: 2
+       interleave: {}
+       keyColumnDirections:
+  ...
+       partitioning: {}
+       sharded: {}
+  -    storeColumnIds:
+  -    - 2
+  -    storeColumnNames:
+  -    - crdb_internal_column_2_name_placeholder
+  +    storeColumnNames: []
+       unique: true
+       version: 4
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "6"
+  +  version: "7"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending"
+set schema change job #1 to non-cancellable
+commit transaction #10
+begin transaction #11
+## PostCommitNonRevertiblePhase stage 2 of 3 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     formatVersion: 3
+     id: 104
+  -  modificationTime:
+  -    wallTime: "1640995200000000010"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 3
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "7"
+  +  version: "8"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 3 of 3 with 5 MutationType ops pending"
+commit transaction #11
+begin transaction #12
+## PostCommitNonRevertiblePhase stage 3 of 3 with 7 MutationType ops
+upsert descriptor #104
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  -  declarativeSchemaChangerState:
+  -    authorization:
+  -      userName: root
+  -    currentStatuses: <redacted>
+  -    jobId: "1"
+  -    relevantStatements:
+  -    - statement:
+  -        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+  -        statement: ALTER TABLE t DROP COLUMN j
+  -        statementTag: ALTER TABLE
+  -    targetRanks: <redacted>
+  -    targets: <redacted>
+     families:
+     - columnIds:
+       - 1
+  -    - 2
+       columnNames:
+       - i
+  -    - crdb_internal_column_2_name_placeholder
+       defaultColumnId: 2
+       name: primary
+     formatVersion: 3
+     id: 104
+  -  modificationTime:
+  -    wallTime: "1640995200000000011"
+  -  mutations:
+  -  - column:
+  -      id: 2
+  -      name: crdb_internal_column_2_name_placeholder
+  -      nullable: true
+  -      type:
+  -        family: IntFamily
+  -        oid: 20
+  -        width: 64
+  -    direction: DROP
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 3
+  -      createdExplicitly: true
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 3
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - i
+  -      name: crdb_internal_index_3_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnNames: []
+  -      unique: true
+  -      useDeletePreservingEncoding: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 1
+  -      createdAtNanos: "1640995200000000000"
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 1
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - i
+  -      name: crdb_internal_index_1_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnIds:
+  -      - 2
+  -      storeColumnNames:
+  -      - crdb_internal_column_2_name_placeholder
+  -      unique: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  +  modificationTime: {}
+  +  mutations: []
+     name: t
+     nextColumnId: 3
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "8"
+  +  version: "9"
+write *eventpb.FinishSchemaChange to event log for descriptor 104
+create job #2 (non-cancelable: true): "GC for ALTER TABLE defaultdb.public.t DROP COLUMN j"
+  descriptor IDs: [104]
+update progress of schema change job #1: "all stages completed"
+commit transaction #12
+notified job registry to adopt jobs: [2]
+# end PostCommitPhase
diff --git a/pkg/sql/schemachanger/testdata/end_to_end/drop_column_computed_index b/pkg/sql/schemachanger/testdata/end_to_end/drop_column_computed_index
new file mode 100644
index 000000000000..b219e215a13c
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/end_to_end/drop_column_computed_index
@@ -0,0 +1,631 @@
+setup
+create table t (i int primary key, j int, index((j+1)));
+----
+...
++object {100 101 t} -> 104
+
+test
+alter table t drop column j cascade;
+----
+begin transaction #1
+# begin StatementPhase
+checking for feature: ALTER TABLE
+increment telemetry for sql.schema.alter_table
+increment telemetry for sql.schema.alter_table.drop_column
+## StatementPhase stage 1 of 1 with 12 MutationType ops
+upsert descriptor #104
+  ...
+         oid: 20
+         width: 64
+  -  - id: 2
+  -    name: j
+  -    nullable: true
+  -    type:
+  -      family: IntFamily
+  -      oid: 20
+  -      width: 64
+  -  - computeExpr: j + 1:::INT8
+  -    id: 3
+  -    inaccessible: true
+  -    name: crdb_internal_idx_expr
+  -    nullable: true
+  -    type:
+  -      family: IntFamily
+  -      oid: 20
+  -      width: 64
+  -    virtual: true
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  ...
+       columnNames:
+       - i
+  -    - j
+  +    - crdb_internal_column_2_name_placeholder
+       defaultColumnId: 2
+       name: primary
+     formatVersion: 3
+     id: 104
+  -  indexes:
+  -  - createdAtNanos: "1640995200000000000"
+  -    foreignKey: {}
+  -    geoConfig: {}
+  -    id: 2
+  -    interleave: {}
+  -    keyColumnDirections:
+  -    - ASC
+  -    keyColumnIds:
+  -    - 3
+  -    keyColumnNames:
+  -    - crdb_internal_idx_expr
+  -    keySuffixColumnIds:
+  -    - 1
+  -    name: t_expr_idx
+  -    partitioning: {}
+  -    sharded: {}
+  -    version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000000"
+  +  indexes: []
+  +  modificationTime: {}
+  +  mutations:
+  +  - column:
+  +      id: 2
+  +      name: crdb_internal_column_2_name_placeholder
+  +      nullable: true
+  +      type:
+  +        family: IntFamily
+  +        oid: 20
+  +        width: 64
+  +    direction: DROP
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - column:
+  +      computeExpr: crdb_internal_column_2_name_placeholder + 1:::INT8
+  +      id: 3
+  +      inaccessible: true
+  +      name: crdb_internal_column_3_name_placeholder
+  +      nullable: true
+  +      type:
+  +        family: IntFamily
+  +        oid: 20
+  +        width: 64
+  +      virtual: true
+  +    direction: DROP
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - direction: DROP
+  +    index:
+  +      createdAtNanos: "1640995200000000000"
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 2
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 3
+  +      keyColumnNames:
+  +      - crdb_internal_column_3_name_placeholder
+  +      keySuffixColumnIds:
+  +      - 1
+  +      name: crdb_internal_index_2_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      version: 3
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 2
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 3
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - i
+  +      name: crdb_internal_index_3_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnNames: []
+  +      unique: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: BACKFILLING
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 3
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 4
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - i
+  +      name: crdb_internal_index_4_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnNames: []
+  +      unique: true
+  +      useDeletePreservingEncoding: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 4
+  -  nextConstraintId: 2
+  +  nextConstraintId: 4
+     nextFamilyId: 1
+  -  nextIndexId: 3
+  +  nextIndexId: 5
+     nextMutationId: 1
+     parentId: 100
+  ...
+       - 2
+       storeColumnNames:
+  -    - j
+  +    - crdb_internal_column_2_name_placeholder
+       unique: true
+       version: 4
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "1"
+  +  version: "2"
+write *eventpb.AlterTable to event log for descriptor #104: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+# end StatementPhase
+# begin PreCommitPhase
+## PreCommitPhase stage 1 of 1 with 2 MutationType ops
+upsert descriptor #104
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  +  declarativeSchemaChangerState:
+  +    authorization:
+  +      userName: root
+  +    currentStatuses: <redacted>
+  +    jobId: "1"
+  +    relevantStatements:
+  +    - statement:
+  +        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+  +        statement: ALTER TABLE t DROP COLUMN j CASCADE
+  +        statementTag: ALTER TABLE
+  +    revertible: true
+  +    targetRanks: <redacted>
+  +    targets: <redacted>
+     families:
+     - columnIds:
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime: {}
+  +  modificationTime:
+  +    wallTime: "1640995200000000001"
+     mutations:
+     - column:
+  ...
+create job #1 (non-cancelable: false): "ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE"
+  descriptor IDs: [104]
+# end PreCommitPhase
+commit transaction #1
+notified job registry to adopt jobs: [1]
+# begin PostCommitPhase
+begin transaction #2
+commit transaction #2
+begin transaction #3
+## PostCommitPhase stage 1 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000001"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: DELETE_AND_WRITE_ONLY
+     name: t
+     nextColumnId: 4
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "2"
+  +  version: "3"
+update progress of schema change job #1: "PostCommitPhase stage 2 of 7 with 1 BackfillType op pending"
+commit transaction #3
+begin transaction #4
+## PostCommitPhase stage 2 of 7 with 1 BackfillType op
+backfill indexes [3] from index #1 in table #104
+commit transaction #4
+begin transaction #5
+## PostCommitPhase stage 3 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000003"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: BACKFILLING
+  +    state: DELETE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "3"
+  +  version: "4"
+update progress of schema change job #1: "PostCommitPhase stage 4 of 7 with 1 MutationType op pending"
+commit transaction #5
+begin transaction #6
+## PostCommitPhase stage 4 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000005"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: MERGING
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "4"
+  +  version: "5"
+update progress of schema change job #1: "PostCommitPhase stage 5 of 7 with 1 BackfillType op pending"
+commit transaction #6
+begin transaction #7
+## PostCommitPhase stage 5 of 7 with 1 BackfillType op
+merge temporary indexes [4] into backfilled indexes [3] in table #104
+commit transaction #7
+begin transaction #8
+## PostCommitPhase stage 6 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "5"
+  +  version: "6"
+update progress of schema change job #1: "PostCommitPhase stage 7 of 7 with 1 ValidationType op pending"
+commit transaction #8
+begin transaction #9
+## PostCommitPhase stage 7 of 7 with 1 ValidationType op
+validate forward indexes [3] in table #104
+commit transaction #9
+begin transaction #10
+## PostCommitNonRevertiblePhase stage 1 of 3 with 14 MutationType ops
+upsert descriptor #104
+  ...
+           statement: ALTER TABLE t DROP COLUMN j CASCADE
+           statementTag: ALTER TABLE
+  -    revertible: true
+       targetRanks: <redacted>
+       targets: <redacted>
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000008"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+       direction: DROP
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     - column:
+         computeExpr: crdb_internal_column_2_name_placeholder + 1:::INT8
+  ...
+       direction: DROP
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     - direction: DROP
+       index:
+  ...
+         version: 3
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 2
+  +      constraintId: 3
+         createdExplicitly: true
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 3
+  +      id: 4
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - i
+  -      name: crdb_internal_index_3_name_placeholder
+  +      name: crdb_internal_index_4_name_placeholder
+         partitioning: {}
+         sharded: {}
+         storeColumnNames: []
+         unique: true
+  +      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 3
+  -      createdExplicitly: true
+  +      constraintId: 1
+  +      createdAtNanos: "1640995200000000000"
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 4
+  +      id: 1
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - i
+  -      name: crdb_internal_index_4_name_placeholder
+  +      name: crdb_internal_index_1_name_placeholder
+         partitioning: {}
+         sharded: {}
+  -      storeColumnNames: []
+  +      storeColumnIds:
+  +      - 2
+  +      storeColumnNames:
+  +      - crdb_internal_column_2_name_placeholder
+         unique: true
+  -      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 1
+  ...
+     parentId: 100
+     primaryIndex:
+  -    constraintId: 1
+  -    createdAtNanos: "1640995200000000000"
+  +    constraintId: 2
+  +    createdExplicitly: true
+       encodingType: 1
+       foreignKey: {}
+       geoConfig: {}
+  -    id: 1
+  +    id: 3
+       interleave: {}
+       keyColumnDirections:
+  ...
+       partitioning: {}
+       sharded: {}
+  -    storeColumnIds:
+  -    - 2
+  -    storeColumnNames:
+  -    - crdb_internal_column_2_name_placeholder
+  +    storeColumnNames: []
+       unique: true
+       version: 4
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "6"
+  +  version: "7"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending"
+set schema change job #1 to non-cancellable
+commit transaction #10
+begin transaction #11
+## PostCommitNonRevertiblePhase stage 2 of 3 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000010"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 4
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "7"
+  +  version: "8"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 3 of 3 with 9 MutationType ops pending"
+commit transaction #11
+begin transaction #12
+## PostCommitNonRevertiblePhase stage 3 of 3 with 11 MutationType ops
+upsert descriptor #104
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  -  declarativeSchemaChangerState:
+  -    authorization:
+  -      userName: root
+  -    currentStatuses: <redacted>
+  -    jobId: "1"
+  -    relevantStatements:
+  -    - statement:
+  -        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+  -        statement: ALTER TABLE t DROP COLUMN j CASCADE
+  -        statementTag: ALTER TABLE
+  -    targetRanks: <redacted>
+  -    targets: <redacted>
+     families:
+     - columnIds:
+       - 1
+  -    - 2
+       columnNames:
+       - i
+  -    - crdb_internal_column_2_name_placeholder
+       defaultColumnId: 2
+       name: primary
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000011"
+  -  mutations:
+  -  - column:
+  -      id: 2
+  -      name: crdb_internal_column_2_name_placeholder
+  -      nullable: true
+  -      type:
+  -        family: IntFamily
+  -        oid: 20
+  -        width: 64
+  -    direction: DROP
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - column:
+  -      computeExpr: crdb_internal_column_2_name_placeholder + 1:::INT8
+  -      id: 3
+  -      inaccessible: true
+  -      name: crdb_internal_column_3_name_placeholder
+  -      nullable: true
+  -      type:
+  -        family: IntFamily
+  -        oid: 20
+  -        width: 64
+  -      virtual: true
+  -    direction: DROP
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      createdAtNanos: "1640995200000000000"
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 2
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 3
+  -      keyColumnNames:
+  -      - crdb_internal_column_3_name_placeholder
+  -      keySuffixColumnIds:
+  -      - 1
+  -      name: crdb_internal_index_2_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      version: 3
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 3
+  -      createdExplicitly: true
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 4
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - i
+  -      name: crdb_internal_index_4_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnNames: []
+  -      unique: true
+  -      useDeletePreservingEncoding: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 1
+  -      createdAtNanos: "1640995200000000000"
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 1
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - i
+  -      name: crdb_internal_index_1_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnIds:
+  -      - 2
+  -      storeColumnNames:
+  -      - crdb_internal_column_2_name_placeholder
+  -      unique: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  +  modificationTime: {}
+  +  mutations: []
+     name: t
+     nextColumnId: 4
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "8"
+  +  version: "9"
+write *eventpb.DropIndex to event log for descriptor #104: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+create job #2 (non-cancelable: true): "GC for ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE"
+  descriptor IDs: [104]
+update progress of schema change job #1: "all stages completed"
+commit transaction #12
+notified job registry to adopt jobs: [2]
+# end PostCommitPhase
diff --git a/pkg/sql/schemachanger/testdata/end_to_end/drop_column_create_index_separate_statements b/pkg/sql/schemachanger/testdata/end_to_end/drop_column_create_index_separate_statements
new file mode 100644
index 000000000000..2fd0952c63c1
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/end_to_end/drop_column_create_index_separate_statements
@@ -0,0 +1,930 @@
+setup
+create table t (i int primary key, j int, k int default 32 on update 42, index((j+1), k));
+----
+...
++object {100 101 t} -> 104
+
+test
+alter table t drop column j cascade;
+create unique index idx on t(k);
+----
+begin transaction #1
+# begin StatementPhase
+checking for feature: ALTER TABLE
+increment telemetry for sql.schema.alter_table
+increment telemetry for sql.schema.alter_table.drop_column
+## StatementPhase stage 1 of 1 with 14 MutationType ops
+upsert descriptor #104
+  ...
+         oid: 20
+         width: 64
+  -  - id: 2
+  -    name: j
+  -    nullable: true
+  -    type:
+  -      family: IntFamily
+  -      oid: 20
+  -      width: 64
+     - defaultExpr: 32:::INT8
+       id: 3
+  ...
+         oid: 20
+         width: 64
+  -  - computeExpr: j + 1:::INT8
+  -    id: 4
+  -    inaccessible: true
+  -    name: crdb_internal_idx_expr
+  -    nullable: true
+  -    type:
+  -      family: IntFamily
+  -      oid: 20
+  -      width: 64
+  -    virtual: true
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  ...
+       columnNames:
+       - i
+  -    - j
+  +    - crdb_internal_column_2_name_placeholder
+       - k
+       name: primary
+     formatVersion: 3
+     id: 104
+  -  indexes:
+  -  - createdAtNanos: "1640995200000000000"
+  -    foreignKey: {}
+  -    geoConfig: {}
+  -    id: 2
+  -    interleave: {}
+  -    keyColumnDirections:
+  -    - ASC
+  -    - ASC
+  -    keyColumnIds:
+  -    - 4
+  -    - 3
+  -    keyColumnNames:
+  -    - crdb_internal_idx_expr
+  -    - k
+  -    keySuffixColumnIds:
+  -    - 1
+  -    name: t_expr_k_idx
+  -    partitioning: {}
+  -    sharded: {}
+  -    version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000000"
+  +  indexes: []
+  +  modificationTime: {}
+  +  mutations:
+  +  - column:
+  +      id: 2
+  +      name: crdb_internal_column_2_name_placeholder
+  +      nullable: true
+  +      type:
+  +        family: IntFamily
+  +        oid: 20
+  +        width: 64
+  +    direction: DROP
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - column:
+  +      computeExpr: crdb_internal_column_2_name_placeholder + 1:::INT8
+  +      id: 4
+  +      inaccessible: true
+  +      name: crdb_internal_column_4_name_placeholder
+  +      nullable: true
+  +      type:
+  +        family: IntFamily
+  +        oid: 20
+  +        width: 64
+  +      virtual: true
+  +    direction: DROP
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - direction: DROP
+  +    index:
+  +      createdAtNanos: "1640995200000000000"
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 2
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      - ASC
+  +      keyColumnIds:
+  +      - 4
+  +      - 3
+  +      keyColumnNames:
+  +      - crdb_internal_column_4_name_placeholder
+  +      - k
+  +      keySuffixColumnIds:
+  +      - 1
+  +      name: crdb_internal_index_2_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      version: 3
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 2
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 3
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - i
+  +      name: crdb_internal_index_3_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnIds:
+  +      - 3
+  +      storeColumnNames:
+  +      - k
+  +      unique: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: BACKFILLING
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 3
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 4
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - i
+  +      name: crdb_internal_index_4_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnIds:
+  +      - 3
+  +      storeColumnNames:
+  +      - k
+  +      unique: true
+  +      useDeletePreservingEncoding: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 5
+  -  nextConstraintId: 2
+  +  nextConstraintId: 4
+     nextFamilyId: 1
+  -  nextIndexId: 3
+  +  nextIndexId: 5
+     nextMutationId: 1
+     parentId: 100
+  ...
+       - 3
+       storeColumnNames:
+  -    - j
+  +    - crdb_internal_column_2_name_placeholder
+       - k
+       unique: true
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "1"
+  +  version: "2"
+write *eventpb.AlterTable to event log for descriptor #104: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+checking for feature: CREATE INDEX
+# end StatementPhase
+# begin PreCommitPhase
+## PreCommitPhase stage 1 of 1 with 2 MutationType ops
+upsert descriptor #104
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  +  declarativeSchemaChangerState:
+  +    authorization:
+  +      userName: root
+  +    currentStatuses: <redacted>
+  +    jobId: "1"
+  +    relevantStatements:
+  +    - statement:
+  +        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+  +        statement: ALTER TABLE t DROP COLUMN j CASCADE
+  +        statementTag: ALTER TABLE
+  +    - statement:
+  +        redactedStatement: CREATE UNIQUE INDEX ‹idx› ON ‹defaultdb›.‹public›.‹t› (‹k›)
+  +        statement: CREATE UNIQUE INDEX idx ON t (k)
+  +        statementTag: CREATE INDEX
+  +      statementRank: 1
+  +    revertible: true
+  +    targetRanks: <redacted>
+  +    targets: <redacted>
+     families:
+     - columnIds:
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime: {}
+  +  modificationTime:
+  +    wallTime: "1640995200000000001"
+     mutations:
+     - column:
+  ...
+create job #1 (non-cancelable: false): "ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE; CREATE UNIQUE INDEX idx ON defaultdb.public.t (k)"
+  descriptor IDs: [104]
+# end PreCommitPhase
+commit transaction #1
+notified job registry to adopt jobs: [1]
+# begin PostCommitPhase
+begin transaction #2
+commit transaction #2
+begin transaction #3
+## PostCommitPhase stage 1 of 15 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000001"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: DELETE_AND_WRITE_ONLY
+     name: t
+     nextColumnId: 5
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "2"
+  +  version: "3"
+update progress of schema change job #1: "PostCommitPhase stage 2 of 15 with 1 BackfillType op pending"
+commit transaction #3
+begin transaction #4
+## PostCommitPhase stage 2 of 15 with 1 BackfillType op
+backfill indexes [3] from index #1 in table #104
+commit transaction #4
+begin transaction #5
+## PostCommitPhase stage 3 of 15 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000003"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: BACKFILLING
+  +    state: DELETE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "3"
+  +  version: "4"
+update progress of schema change job #1: "PostCommitPhase stage 4 of 15 with 1 MutationType op pending"
+commit transaction #5
+begin transaction #6
+## PostCommitPhase stage 4 of 15 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000005"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: MERGING
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "4"
+  +  version: "5"
+update progress of schema change job #1: "PostCommitPhase stage 5 of 15 with 1 BackfillType op pending"
+commit transaction #6
+begin transaction #7
+## PostCommitPhase stage 5 of 15 with 1 BackfillType op
+merge temporary indexes [4] into backfilled indexes [3] in table #104
+commit transaction #7
+begin transaction #8
+## PostCommitPhase stage 6 of 15 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "5"
+  +  version: "6"
+update progress of schema change job #1: "PostCommitPhase stage 7 of 15 with 1 ValidationType op pending"
+commit transaction #8
+begin transaction #9
+## PostCommitPhase stage 7 of 15 with 1 ValidationType op
+validate forward indexes [3] in table #104
+commit transaction #9
+begin transaction #10
+## PostCommitPhase stage 8 of 15 with 12 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000008"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+     - direction: ADD
+       index:
+  -      constraintId: 2
+  +      constraintId: 3
+         createdExplicitly: true
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 3
+  +      id: 4
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - i
+  -      name: crdb_internal_index_3_name_placeholder
+  +      name: crdb_internal_index_4_name_placeholder
+         partitioning: {}
+         sharded: {}
+  ...
+         - k
+         unique: true
+  +      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 1
+       state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +  - direction: DROP
+       index:
+  -      constraintId: 3
+  -      createdExplicitly: true
+  +      constraintId: 1
+  +      createdAtNanos: "1640995200000000000"
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 4
+  +      id: 1
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - i
+  -      name: crdb_internal_index_4_name_placeholder
+  +      name: crdb_internal_index_1_name_placeholder
+         partitioning: {}
+         sharded: {}
+         storeColumnIds:
+  +      - 2
+         - 3
+         storeColumnNames:
+  +      - crdb_internal_column_2_name_placeholder
+         - k
+         unique: true
+  -      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 1
+       state: DELETE_AND_WRITE_ONLY
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 4
+  +      createdExplicitly: true
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 5
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 3
+  +      keyColumnNames:
+  +      - k
+  +      keySuffixColumnIds:
+  +      - 1
+  +      name: crdb_internal_index_5_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnNames: []
+  +      unique: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: BACKFILLING
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 5
+  +      createdExplicitly: true
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 6
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 3
+  +      keyColumnNames:
+  +      - k
+  +      keySuffixColumnIds:
+  +      - 1
+  +      name: crdb_internal_index_6_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnNames: []
+  +      unique: true
+  +      useDeletePreservingEncoding: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 5
+  -  nextConstraintId: 4
+  +  nextConstraintId: 6
+     nextFamilyId: 1
+  -  nextIndexId: 5
+  +  nextIndexId: 7
+     nextMutationId: 1
+     parentId: 100
+     primaryIndex:
+  -    constraintId: 1
+  -    createdAtNanos: "1640995200000000000"
+  +    constraintId: 2
+  +    createdExplicitly: true
+       encodingType: 1
+       foreignKey: {}
+       geoConfig: {}
+  -    id: 1
+  +    id: 3
+       interleave: {}
+       keyColumnDirections:
+  ...
+       sharded: {}
+       storeColumnIds:
+  -    - 2
+       - 3
+       storeColumnNames:
+  -    - crdb_internal_column_2_name_placeholder
+       - k
+       unique: true
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "6"
+  +  version: "7"
+update progress of schema change job #1: "PostCommitPhase stage 9 of 15 with 1 MutationType op pending"
+commit transaction #10
+begin transaction #11
+## PostCommitPhase stage 9 of 15 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000010"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: DELETE_AND_WRITE_ONLY
+     name: t
+     nextColumnId: 5
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "7"
+  +  version: "8"
+update progress of schema change job #1: "PostCommitPhase stage 10 of 15 with 1 BackfillType op pending"
+commit transaction #11
+begin transaction #12
+## PostCommitPhase stage 10 of 15 with 1 BackfillType op
+backfill indexes [5] from index #3 in table #104
+commit transaction #12
+begin transaction #13
+## PostCommitPhase stage 11 of 15 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000011"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: BACKFILLING
+  +    state: DELETE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "8"
+  +  version: "9"
+update progress of schema change job #1: "PostCommitPhase stage 12 of 15 with 1 MutationType op pending"
+commit transaction #13
+begin transaction #14
+## PostCommitPhase stage 12 of 15 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000013"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: MERGING
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "9"
+  +  version: "10"
+update progress of schema change job #1: "PostCommitPhase stage 13 of 15 with 1 BackfillType op pending"
+commit transaction #14
+begin transaction #15
+## PostCommitPhase stage 13 of 15 with 1 BackfillType op
+merge temporary indexes [6] into backfilled indexes [5] in table #104
+commit transaction #15
+begin transaction #16
+## PostCommitPhase stage 14 of 15 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000014"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "10"
+  +  version: "11"
+update progress of schema change job #1: "PostCommitPhase stage 15 of 15 with 1 ValidationType op pending"
+commit transaction #16
+begin transaction #17
+## PostCommitPhase stage 15 of 15 with 1 ValidationType op
+validate forward indexes [5] in table #104
+commit transaction #17
+begin transaction #18
+## PostCommitNonRevertiblePhase stage 1 of 2 with 16 MutationType ops
+upsert descriptor #104
+  ...
+           statementTag: CREATE INDEX
+         statementRank: 1
+  -    revertible: true
+       targetRanks: <redacted>
+       targets: <redacted>
+  ...
+     formatVersion: 3
+     id: 104
+  -  indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000016"
+  +  indexes:
+  +  - constraintId: 4
+  +    createdExplicitly: true
+  +    foreignKey: {}
+  +    geoConfig: {}
+  +    id: 5
+  +    interleave: {}
+  +    keyColumnDirections:
+  +    - ASC
+  +    keyColumnIds:
+  +    - 3
+  +    keyColumnNames:
+  +    - k
+  +    keySuffixColumnIds:
+  +    - 1
+  +    name: idx
+  +    partitioning: {}
+  +    sharded: {}
+  +    storeColumnNames: []
+  +    unique: true
+  +    version: 4
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+       direction: DROP
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     - column:
+         computeExpr: crdb_internal_column_2_name_placeholder + 1:::INT8
+  ...
+       direction: DROP
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     - direction: DROP
+       index:
+  ...
+         version: 3
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+         constraintId: 3
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     - direction: DROP
+       index:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 4
+  -      createdExplicitly: true
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 5
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 3
+  -      keyColumnNames:
+  -      - k
+  -      keySuffixColumnIds:
+  -      - 1
+  -      name: crdb_internal_index_5_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnNames: []
+  -      unique: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  -    index:
+         constraintId: 5
+         createdExplicitly: true
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 5
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "11"
+  +  version: "12"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 2 of 2 with 11 MutationType ops pending"
+set schema change job #1 to non-cancellable
+commit transaction #18
+begin transaction #19
+## PostCommitNonRevertiblePhase stage 2 of 2 with 13 MutationType ops
+upsert descriptor #104
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  -  declarativeSchemaChangerState:
+  -    authorization:
+  -      userName: root
+  -    currentStatuses: <redacted>
+  -    jobId: "1"
+  -    relevantStatements:
+  -    - statement:
+  -        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+  -        statement: ALTER TABLE t DROP COLUMN j CASCADE
+  -        statementTag: ALTER TABLE
+  -    - statement:
+  -        redactedStatement: CREATE UNIQUE INDEX ‹idx› ON ‹defaultdb›.‹public›.‹t› (‹k›)
+  -        statement: CREATE UNIQUE INDEX idx ON t (k)
+  -        statementTag: CREATE INDEX
+  -      statementRank: 1
+  -    targetRanks: <redacted>
+  -    targets: <redacted>
+     families:
+     - columnIds:
+       - 1
+  -    - 2
+       - 3
+       columnNames:
+       - i
+  -    - crdb_internal_column_2_name_placeholder
+       - k
+       name: primary
+  ...
+       unique: true
+       version: 4
+  -  modificationTime:
+  -    wallTime: "1640995200000000018"
+  -  mutations:
+  -  - column:
+  -      id: 2
+  -      name: crdb_internal_column_2_name_placeholder
+  -      nullable: true
+  -      type:
+  -        family: IntFamily
+  -        oid: 20
+  -        width: 64
+  -    direction: DROP
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - column:
+  -      computeExpr: crdb_internal_column_2_name_placeholder + 1:::INT8
+  -      id: 4
+  -      inaccessible: true
+  -      name: crdb_internal_column_4_name_placeholder
+  -      nullable: true
+  -      type:
+  -        family: IntFamily
+  -        oid: 20
+  -        width: 64
+  -      virtual: true
+  -    direction: DROP
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      createdAtNanos: "1640995200000000000"
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 2
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      - ASC
+  -      keyColumnIds:
+  -      - 4
+  -      - 3
+  -      keyColumnNames:
+  -      - crdb_internal_column_4_name_placeholder
+  -      - k
+  -      keySuffixColumnIds:
+  -      - 1
+  -      name: crdb_internal_index_2_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      version: 3
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 3
+  -      createdExplicitly: true
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 4
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - i
+  -      name: crdb_internal_index_4_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnIds:
+  -      - 3
+  -      storeColumnNames:
+  -      - k
+  -      unique: true
+  -      useDeletePreservingEncoding: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 1
+  -      createdAtNanos: "1640995200000000000"
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 1
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - i
+  -      name: crdb_internal_index_1_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnIds:
+  -      - 2
+  -      - 3
+  -      storeColumnNames:
+  -      - crdb_internal_column_2_name_placeholder
+  -      - k
+  -      unique: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 5
+  -      createdExplicitly: true
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 6
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 3
+  -      keyColumnNames:
+  -      - k
+  -      keySuffixColumnIds:
+  -      - 1
+  -      name: crdb_internal_index_6_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnNames: []
+  -      unique: true
+  -      useDeletePreservingEncoding: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  +  modificationTime: {}
+  +  mutations: []
+     name: t
+     nextColumnId: 5
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "12"
+  +  version: "13"
+write *eventpb.DropIndex to event log for descriptor #104: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+create job #2 (non-cancelable: true): "GC for ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE"
+  descriptor IDs: [104]
+update progress of schema change job #1: "all stages completed"
+commit transaction #19
+notified job registry to adopt jobs: [2]
+# end PostCommitPhase
diff --git a/pkg/sql/schemachanger/testdata/end_to_end/drop_column_unique_index b/pkg/sql/schemachanger/testdata/end_to_end/drop_column_unique_index
new file mode 100644
index 000000000000..419d799ce238
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/end_to_end/drop_column_unique_index
@@ -0,0 +1,550 @@
+setup
+CREATE DATABASE t;
+CREATE TABLE t.test (k INT PRIMARY KEY, v INT, pi DECIMAL DEFAULT (DECIMAL '3.14'));
+CREATE UNIQUE INDEX vidx ON t.test (v);
+ALTER TABLE t.test ADD COLUMN x DECIMAL DEFAULT (DECIMAL '1.4') CHECK (x >= 0);
+----
+...
++database {0 0 t} -> 104
++schema {104 0 public} -> 105
++object {104 105 test} -> 106
+
+test
+ALTER TABLE t.test DROP pi
+----
+begin transaction #1
+# begin StatementPhase
+checking for feature: ALTER TABLE
+increment telemetry for sql.schema.alter_table
+increment telemetry for sql.schema.alter_table.drop_column
+## StatementPhase stage 1 of 1 with 11 MutationType ops
+upsert descriptor #106
+  ...
+         oid: 20
+         width: 64
+  -  - defaultExpr: 3.14:::DECIMAL
+  -    id: 3
+  -    name: pi
+  -    nullable: true
+  -    type:
+  -      family: DecimalFamily
+  -      oid: 1700
+     - defaultExpr: 1.4:::DECIMAL
+       id: 4
+  ...
+       - k
+       - v
+  -    - pi
+  +    - crdb_internal_column_3_name_placeholder
+       - x
+       name: primary
+  ...
+       unique: true
+       version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000000"
+  +  modificationTime: {}
+  +  mutations:
+  +  - column:
+  +      defaultExpr: 3.14:::DECIMAL
+  +      id: 3
+  +      name: crdb_internal_column_3_name_placeholder
+  +      nullable: true
+  +      type:
+  +        family: DecimalFamily
+  +        oid: 1700
+  +    direction: DROP
+  +    mutationId: 3
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 8
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 4
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - k
+  +      name: crdb_internal_index_4_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnIds:
+  +      - 2
+  +      - 4
+  +      storeColumnNames:
+  +      - v
+  +      - x
+  +      unique: true
+  +      version: 4
+  +    mutationId: 3
+  +    state: BACKFILLING
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 9
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 5
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - k
+  +      name: crdb_internal_index_5_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnIds:
+  +      - 2
+  +      - 4
+  +      storeColumnNames:
+  +      - v
+  +      - x
+  +      unique: true
+  +      useDeletePreservingEncoding: true
+  +      version: 4
+  +    mutationId: 3
+  +    state: DELETE_ONLY
+     name: test
+     nextColumnId: 5
+  -  nextConstraintId: 8
+  +  nextConstraintId: 10
+     nextFamilyId: 1
+  -  nextIndexId: 4
+  +  nextIndexId: 6
+     nextMutationId: 3
+     parentId: 104
+  ...
+       storeColumnNames:
+       - v
+  -    - pi
+  +    - crdb_internal_column_3_name_placeholder
+       - x
+       unique: true
+  ...
+       time: {}
+     unexposedParentSchemaId: 105
+  -  version: "11"
+  +  version: "12"
+write *eventpb.AlterTable to event log for descriptor #106: ALTER TABLE ‹t›.‹public›.‹test› DROP COLUMN ‹pi›
+# end StatementPhase
+# begin PreCommitPhase
+## PreCommitPhase stage 1 of 1 with 2 MutationType ops
+upsert descriptor #106
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  +  declarativeSchemaChangerState:
+  +    authorization:
+  +      userName: root
+  +    currentStatuses: <redacted>
+  +    jobId: "1"
+  +    relevantStatements:
+  +    - statement:
+  +        redactedStatement: ALTER TABLE ‹t›.‹public›.‹test› DROP COLUMN ‹pi›
+  +        statement: ALTER TABLE t.test DROP COLUMN pi
+  +        statementTag: ALTER TABLE
+  +    revertible: true
+  +    targetRanks: <redacted>
+  +    targets: <redacted>
+     families:
+     - columnIds:
+  ...
+       unique: true
+       version: 3
+  -  modificationTime: {}
+  +  modificationTime:
+  +    wallTime: "1640995200000000001"
+     mutations:
+     - column:
+  ...
+create job #1 (non-cancelable: false): "ALTER TABLE t.public.test DROP COLUMN pi"
+  descriptor IDs: [106]
+# end PreCommitPhase
+commit transaction #1
+notified job registry to adopt jobs: [1]
+# begin PostCommitPhase
+begin transaction #2
+commit transaction #2
+begin transaction #3
+## PostCommitPhase stage 1 of 7 with 3 MutationType ops
+upsert descriptor #106
+  ...
+       unique: true
+       version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000001"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 3
+  -    state: DELETE_ONLY
+  +    state: DELETE_AND_WRITE_ONLY
+     name: test
+     nextColumnId: 5
+  ...
+       time: {}
+     unexposedParentSchemaId: 105
+  -  version: "12"
+  +  version: "13"
+update progress of schema change job #1: "PostCommitPhase stage 2 of 7 with 1 BackfillType op pending"
+commit transaction #3
+begin transaction #4
+## PostCommitPhase stage 2 of 7 with 1 BackfillType op
+backfill indexes [4] from index #1 in table #106
+commit transaction #4
+begin transaction #5
+## PostCommitPhase stage 3 of 7 with 3 MutationType ops
+upsert descriptor #106
+  ...
+       unique: true
+       version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000003"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 3
+  -    state: BACKFILLING
+  +    state: DELETE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 105
+  -  version: "13"
+  +  version: "14"
+update progress of schema change job #1: "PostCommitPhase stage 4 of 7 with 1 MutationType op pending"
+commit transaction #5
+begin transaction #6
+## PostCommitPhase stage 4 of 7 with 3 MutationType ops
+upsert descriptor #106
+  ...
+       unique: true
+       version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000005"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 3
+  -    state: DELETE_ONLY
+  +    state: MERGING
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 105
+  -  version: "14"
+  +  version: "15"
+update progress of schema change job #1: "PostCommitPhase stage 5 of 7 with 1 BackfillType op pending"
+commit transaction #6
+begin transaction #7
+## PostCommitPhase stage 5 of 7 with 1 BackfillType op
+merge temporary indexes [5] into backfilled indexes [4] in table #106
+commit transaction #7
+begin transaction #8
+## PostCommitPhase stage 6 of 7 with 3 MutationType ops
+upsert descriptor #106
+  ...
+       unique: true
+       version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 3
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 105
+  -  version: "15"
+  +  version: "16"
+update progress of schema change job #1: "PostCommitPhase stage 7 of 7 with 1 ValidationType op pending"
+commit transaction #8
+begin transaction #9
+## PostCommitPhase stage 7 of 7 with 1 ValidationType op
+validate forward indexes [4] in table #106
+commit transaction #9
+begin transaction #10
+## PostCommitNonRevertiblePhase stage 1 of 3 with 12 MutationType ops
+upsert descriptor #106
+  ...
+           statement: ALTER TABLE t.test DROP COLUMN pi
+           statementTag: ALTER TABLE
+  -    revertible: true
+       targetRanks: <redacted>
+       targets: <redacted>
+  ...
+       unique: true
+       version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000008"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+       direction: DROP
+       mutationId: 3
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 8
+  +      constraintId: 9
+         createdExplicitly: true
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 4
+  +      id: 5
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - k
+  -      name: crdb_internal_index_4_name_placeholder
+  +      name: crdb_internal_index_5_name_placeholder
+         partitioning: {}
+         sharded: {}
+  ...
+         - x
+         unique: true
+  +      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 3
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 9
+  -      createdExplicitly: true
+  +      constraintId: 1
+  +      createdAtNanos: "1640995200000000000"
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 5
+  +      id: 1
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - k
+  -      name: crdb_internal_index_5_name_placeholder
+  +      name: crdb_internal_index_1_name_placeholder
+         partitioning: {}
+         sharded: {}
+         storeColumnIds:
+         - 2
+  +      - 3
+         - 4
+         storeColumnNames:
+         - v
+  +      - crdb_internal_column_3_name_placeholder
+         - x
+         unique: true
+  -      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 3
+  ...
+     parentId: 104
+     primaryIndex:
+  -    constraintId: 1
+  -    createdAtNanos: "1640995200000000000"
+  +    constraintId: 8
+  +    createdExplicitly: true
+       encodingType: 1
+       foreignKey: {}
+       geoConfig: {}
+  -    id: 1
+  +    id: 4
+       interleave: {}
+       keyColumnDirections:
+  ...
+       storeColumnIds:
+       - 2
+  -    - 3
+       - 4
+       storeColumnNames:
+       - v
+  -    - crdb_internal_column_3_name_placeholder
+       - x
+       unique: true
+  ...
+       time: {}
+     unexposedParentSchemaId: 105
+  -  version: "16"
+  +  version: "17"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending"
+set schema change job #1 to non-cancellable
+commit transaction #10
+begin transaction #11
+## PostCommitNonRevertiblePhase stage 2 of 3 with 3 MutationType ops
+upsert descriptor #106
+  ...
+       unique: true
+       version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000010"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 3
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     name: test
+     nextColumnId: 5
+  ...
+       time: {}
+     unexposedParentSchemaId: 105
+  -  version: "17"
+  +  version: "18"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 3 of 3 with 6 MutationType ops pending"
+commit transaction #11
+begin transaction #12
+## PostCommitNonRevertiblePhase stage 3 of 3 with 8 MutationType ops
+upsert descriptor #106
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  -  declarativeSchemaChangerState:
+  -    authorization:
+  -      userName: root
+  -    currentStatuses: <redacted>
+  -    jobId: "1"
+  -    relevantStatements:
+  -    - statement:
+  -        redactedStatement: ALTER TABLE ‹t›.‹public›.‹test› DROP COLUMN ‹pi›
+  -        statement: ALTER TABLE t.test DROP COLUMN pi
+  -        statementTag: ALTER TABLE
+  -    targetRanks: <redacted>
+  -    targets: <redacted>
+     families:
+     - columnIds:
+       - 1
+       - 2
+  -    - 3
+       - 4
+       columnNames:
+       - k
+       - v
+  -    - crdb_internal_column_3_name_placeholder
+       - x
+       name: primary
+  ...
+       unique: true
+       version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000011"
+  -  mutations:
+  -  - column:
+  -      defaultExpr: 3.14:::DECIMAL
+  -      id: 3
+  -      name: crdb_internal_column_3_name_placeholder
+  -      nullable: true
+  -      type:
+  -        family: DecimalFamily
+  -        oid: 1700
+  -    direction: DROP
+  -    mutationId: 3
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 9
+  -      createdExplicitly: true
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 5
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - k
+  -      name: crdb_internal_index_5_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnIds:
+  -      - 2
+  -      - 4
+  -      storeColumnNames:
+  -      - v
+  -      - x
+  -      unique: true
+  -      useDeletePreservingEncoding: true
+  -      version: 4
+  -    mutationId: 3
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 1
+  -      createdAtNanos: "1640995200000000000"
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 1
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - k
+  -      name: crdb_internal_index_1_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnIds:
+  -      - 2
+  -      - 3
+  -      - 4
+  -      storeColumnNames:
+  -      - v
+  -      - crdb_internal_column_3_name_placeholder
+  -      - x
+  -      unique: true
+  -      version: 4
+  -    mutationId: 3
+  -    state: DELETE_ONLY
+  +  modificationTime: {}
+  +  mutations: []
+     name: test
+     nextColumnId: 5
+  ...
+       time: {}
+     unexposedParentSchemaId: 105
+  -  version: "18"
+  +  version: "19"
+write *eventpb.FinishSchemaChange to event log for descriptor 106
+create job #2 (non-cancelable: true): "GC for ALTER TABLE t.public.test DROP COLUMN pi"
+  descriptor IDs: [106]
+update progress of schema change job #1: "all stages completed"
+commit transaction #12
+notified job registry to adopt jobs: [2]
+# end PostCommitPhase
diff --git a/pkg/sql/schemachanger/testdata/end_to_end/drop_column_with_index b/pkg/sql/schemachanger/testdata/end_to_end/drop_column_with_index
new file mode 100644
index 000000000000..363c760ea6e8
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/end_to_end/drop_column_with_index
@@ -0,0 +1,586 @@
+setup
+create table t (i int primary key, j int, index (j))
+----
+...
++object {100 101 t} -> 104
+
+test
+alter table t drop column j
+----
+begin transaction #1
+# begin StatementPhase
+checking for feature: ALTER TABLE
+increment telemetry for sql.schema.alter_table
+increment telemetry for sql.schema.alter_table.drop_column
+## StatementPhase stage 1 of 1 with 9 MutationType ops
+upsert descriptor #104
+  ...
+         oid: 20
+         width: 64
+  -  - id: 2
+  -    name: j
+  -    nullable: true
+  -    type:
+  -      family: IntFamily
+  -      oid: 20
+  -      width: 64
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  ...
+       columnNames:
+       - i
+  -    - j
+  +    - crdb_internal_column_2_name_placeholder
+       defaultColumnId: 2
+       name: primary
+     formatVersion: 3
+     id: 104
+  -  indexes:
+  -  - createdAtNanos: "1640995200000000000"
+  -    foreignKey: {}
+  -    geoConfig: {}
+  -    id: 2
+  -    interleave: {}
+  -    keyColumnDirections:
+  -    - ASC
+  -    keyColumnIds:
+  -    - 2
+  -    keyColumnNames:
+  -    - j
+  -    keySuffixColumnIds:
+  -    - 1
+  -    name: t_j_idx
+  -    partitioning: {}
+  -    sharded: {}
+  -    version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000000"
+  +  indexes: []
+  +  modificationTime: {}
+  +  mutations:
+  +  - column:
+  +      id: 2
+  +      name: crdb_internal_column_2_name_placeholder
+  +      nullable: true
+  +      type:
+  +        family: IntFamily
+  +        oid: 20
+  +        width: 64
+  +    direction: DROP
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - direction: DROP
+  +    index:
+  +      createdAtNanos: "1640995200000000000"
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 2
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 2
+  +      keyColumnNames:
+  +      - crdb_internal_column_2_name_placeholder
+  +      keySuffixColumnIds:
+  +      - 1
+  +      name: crdb_internal_index_2_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      version: 3
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 2
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 3
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - i
+  +      name: crdb_internal_index_3_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnNames: []
+  +      unique: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: BACKFILLING
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 3
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 4
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - i
+  +      name: crdb_internal_index_4_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnNames: []
+  +      unique: true
+  +      useDeletePreservingEncoding: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 3
+  -  nextConstraintId: 2
+  +  nextConstraintId: 4
+     nextFamilyId: 1
+  -  nextIndexId: 3
+  +  nextIndexId: 5
+     nextMutationId: 1
+     parentId: 100
+  ...
+       - 2
+       storeColumnNames:
+  -    - j
+  +    - crdb_internal_column_2_name_placeholder
+       unique: true
+       version: 4
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "1"
+  +  version: "2"
+write *eventpb.AlterTable to event log for descriptor #104: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+# end StatementPhase
+# begin PreCommitPhase
+## PreCommitPhase stage 1 of 1 with 2 MutationType ops
+upsert descriptor #104
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  +  declarativeSchemaChangerState:
+  +    authorization:
+  +      userName: root
+  +    currentStatuses: <redacted>
+  +    jobId: "1"
+  +    relevantStatements:
+  +    - statement:
+  +        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+  +        statement: ALTER TABLE t DROP COLUMN j
+  +        statementTag: ALTER TABLE
+  +    revertible: true
+  +    targetRanks: <redacted>
+  +    targets: <redacted>
+     families:
+     - columnIds:
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime: {}
+  +  modificationTime:
+  +    wallTime: "1640995200000000001"
+     mutations:
+     - column:
+  ...
+create job #1 (non-cancelable: false): "ALTER TABLE defaultdb.public.t DROP COLUMN j"
+  descriptor IDs: [104]
+# end PreCommitPhase
+commit transaction #1
+notified job registry to adopt jobs: [1]
+# begin PostCommitPhase
+begin transaction #2
+commit transaction #2
+begin transaction #3
+## PostCommitPhase stage 1 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000001"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: DELETE_AND_WRITE_ONLY
+     name: t
+     nextColumnId: 3
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "2"
+  +  version: "3"
+update progress of schema change job #1: "PostCommitPhase stage 2 of 7 with 1 BackfillType op pending"
+commit transaction #3
+begin transaction #4
+## PostCommitPhase stage 2 of 7 with 1 BackfillType op
+backfill indexes [3] from index #1 in table #104
+commit transaction #4
+begin transaction #5
+## PostCommitPhase stage 3 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000003"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: BACKFILLING
+  +    state: DELETE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "3"
+  +  version: "4"
+update progress of schema change job #1: "PostCommitPhase stage 4 of 7 with 1 MutationType op pending"
+commit transaction #5
+begin transaction #6
+## PostCommitPhase stage 4 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000005"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: MERGING
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "4"
+  +  version: "5"
+update progress of schema change job #1: "PostCommitPhase stage 5 of 7 with 1 BackfillType op pending"
+commit transaction #6
+begin transaction #7
+## PostCommitPhase stage 5 of 7 with 1 BackfillType op
+merge temporary indexes [4] into backfilled indexes [3] in table #104
+commit transaction #7
+begin transaction #8
+## PostCommitPhase stage 6 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "5"
+  +  version: "6"
+update progress of schema change job #1: "PostCommitPhase stage 7 of 7 with 1 ValidationType op pending"
+commit transaction #8
+begin transaction #9
+## PostCommitPhase stage 7 of 7 with 1 ValidationType op
+validate forward indexes [3] in table #104
+commit transaction #9
+begin transaction #10
+## PostCommitNonRevertiblePhase stage 1 of 3 with 13 MutationType ops
+upsert descriptor #104
+  ...
+           statement: ALTER TABLE t DROP COLUMN j
+           statementTag: ALTER TABLE
+  -    revertible: true
+       targetRanks: <redacted>
+       targets: <redacted>
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000008"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+       direction: DROP
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     - direction: DROP
+       index:
+  ...
+         version: 3
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 2
+  +      constraintId: 3
+         createdExplicitly: true
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 3
+  +      id: 4
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - i
+  -      name: crdb_internal_index_3_name_placeholder
+  +      name: crdb_internal_index_4_name_placeholder
+         partitioning: {}
+         sharded: {}
+         storeColumnNames: []
+         unique: true
+  +      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 3
+  -      createdExplicitly: true
+  +      constraintId: 1
+  +      createdAtNanos: "1640995200000000000"
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 4
+  +      id: 1
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - i
+  -      name: crdb_internal_index_4_name_placeholder
+  +      name: crdb_internal_index_1_name_placeholder
+         partitioning: {}
+         sharded: {}
+  -      storeColumnNames: []
+  +      storeColumnIds:
+  +      - 2
+  +      storeColumnNames:
+  +      - crdb_internal_column_2_name_placeholder
+         unique: true
+  -      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 1
+  ...
+     parentId: 100
+     primaryIndex:
+  -    constraintId: 1
+  -    createdAtNanos: "1640995200000000000"
+  +    constraintId: 2
+  +    createdExplicitly: true
+       encodingType: 1
+       foreignKey: {}
+       geoConfig: {}
+  -    id: 1
+  +    id: 3
+       interleave: {}
+       keyColumnDirections:
+  ...
+       partitioning: {}
+       sharded: {}
+  -    storeColumnIds:
+  -    - 2
+  -    storeColumnNames:
+  -    - crdb_internal_column_2_name_placeholder
+  +    storeColumnNames: []
+       unique: true
+       version: 4
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "6"
+  +  version: "7"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending"
+set schema change job #1 to non-cancellable
+commit transaction #10
+begin transaction #11
+## PostCommitNonRevertiblePhase stage 2 of 3 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000010"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 3
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "7"
+  +  version: "8"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 3 of 3 with 8 MutationType ops pending"
+commit transaction #11
+begin transaction #12
+## PostCommitNonRevertiblePhase stage 3 of 3 with 10 MutationType ops
+upsert descriptor #104
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  -  declarativeSchemaChangerState:
+  -    authorization:
+  -      userName: root
+  -    currentStatuses: <redacted>
+  -    jobId: "1"
+  -    relevantStatements:
+  -    - statement:
+  -        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+  -        statement: ALTER TABLE t DROP COLUMN j
+  -        statementTag: ALTER TABLE
+  -    targetRanks: <redacted>
+  -    targets: <redacted>
+     families:
+     - columnIds:
+       - 1
+  -    - 2
+       columnNames:
+       - i
+  -    - crdb_internal_column_2_name_placeholder
+       defaultColumnId: 2
+       name: primary
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000011"
+  -  mutations:
+  -  - column:
+  -      id: 2
+  -      name: crdb_internal_column_2_name_placeholder
+  -      nullable: true
+  -      type:
+  -        family: IntFamily
+  -        oid: 20
+  -        width: 64
+  -    direction: DROP
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      createdAtNanos: "1640995200000000000"
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 2
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 2
+  -      keyColumnNames:
+  -      - crdb_internal_column_2_name_placeholder
+  -      keySuffixColumnIds:
+  -      - 1
+  -      name: crdb_internal_index_2_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      version: 3
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 3
+  -      createdExplicitly: true
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 4
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - i
+  -      name: crdb_internal_index_4_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnNames: []
+  -      unique: true
+  -      useDeletePreservingEncoding: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 1
+  -      createdAtNanos: "1640995200000000000"
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 1
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - i
+  -      name: crdb_internal_index_1_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnIds:
+  -      - 2
+  -      storeColumnNames:
+  -      - crdb_internal_column_2_name_placeholder
+  -      unique: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  +  modificationTime: {}
+  +  mutations: []
+     name: t
+     nextColumnId: 3
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "8"
+  +  version: "9"
+write *eventpb.DropIndex to event log for descriptor #104: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+create job #2 (non-cancelable: true): "GC for ALTER TABLE defaultdb.public.t DROP COLUMN j"
+  descriptor IDs: [104]
+update progress of schema change job #1: "all stages completed"
+commit transaction #12
+notified job registry to adopt jobs: [2]
+# end PostCommitPhase
diff --git a/pkg/sql/schemachanger/testdata/end_to_end/drop_multiple_columns_separate_statements b/pkg/sql/schemachanger/testdata/end_to_end/drop_multiple_columns_separate_statements
new file mode 100644
index 000000000000..e0f111c3bd5c
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/end_to_end/drop_multiple_columns_separate_statements
@@ -0,0 +1,790 @@
+setup
+create table t (i int primary key, j int, k int default 32 on update 42, index((j+1), k));
+----
+...
++object {100 101 t} -> 104
+
+test
+alter table t drop column j cascade;
+alter table t drop column k cascade;
+----
+begin transaction #1
+# begin StatementPhase
+checking for feature: ALTER TABLE
+increment telemetry for sql.schema.alter_table
+increment telemetry for sql.schema.alter_table.drop_column
+## StatementPhase stage 1 of 1 with 14 MutationType ops
+upsert descriptor #104
+  ...
+         oid: 20
+         width: 64
+  -  - id: 2
+  -    name: j
+  -    nullable: true
+  -    type:
+  -      family: IntFamily
+  -      oid: 20
+  -      width: 64
+     - defaultExpr: 32:::INT8
+       id: 3
+  ...
+         oid: 20
+         width: 64
+  -  - computeExpr: j + 1:::INT8
+  -    id: 4
+  -    inaccessible: true
+  -    name: crdb_internal_idx_expr
+  -    nullable: true
+  -    type:
+  -      family: IntFamily
+  -      oid: 20
+  -      width: 64
+  -    virtual: true
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  ...
+       columnNames:
+       - i
+  -    - j
+  +    - crdb_internal_column_2_name_placeholder
+       - k
+       name: primary
+     formatVersion: 3
+     id: 104
+  -  indexes:
+  -  - createdAtNanos: "1640995200000000000"
+  -    foreignKey: {}
+  -    geoConfig: {}
+  -    id: 2
+  -    interleave: {}
+  -    keyColumnDirections:
+  -    - ASC
+  -    - ASC
+  -    keyColumnIds:
+  -    - 4
+  -    - 3
+  -    keyColumnNames:
+  -    - crdb_internal_idx_expr
+  -    - k
+  -    keySuffixColumnIds:
+  -    - 1
+  -    name: t_expr_k_idx
+  -    partitioning: {}
+  -    sharded: {}
+  -    version: 3
+  -  modificationTime:
+  -    wallTime: "1640995200000000000"
+  +  indexes: []
+  +  modificationTime: {}
+  +  mutations:
+  +  - column:
+  +      id: 2
+  +      name: crdb_internal_column_2_name_placeholder
+  +      nullable: true
+  +      type:
+  +        family: IntFamily
+  +        oid: 20
+  +        width: 64
+  +    direction: DROP
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - column:
+  +      computeExpr: crdb_internal_column_2_name_placeholder + 1:::INT8
+  +      id: 4
+  +      inaccessible: true
+  +      name: crdb_internal_column_4_name_placeholder
+  +      nullable: true
+  +      type:
+  +        family: IntFamily
+  +        oid: 20
+  +        width: 64
+  +      virtual: true
+  +    direction: DROP
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - direction: DROP
+  +    index:
+  +      createdAtNanos: "1640995200000000000"
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 2
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      - ASC
+  +      keyColumnIds:
+  +      - 4
+  +      - 3
+  +      keyColumnNames:
+  +      - crdb_internal_column_4_name_placeholder
+  +      - k
+  +      keySuffixColumnIds:
+  +      - 1
+  +      name: crdb_internal_index_2_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      version: 3
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 2
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 3
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - i
+  +      name: crdb_internal_index_3_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnIds:
+  +      - 3
+  +      storeColumnNames:
+  +      - k
+  +      unique: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: BACKFILLING
+  +  - direction: ADD
+  +    index:
+  +      constraintId: 3
+  +      createdExplicitly: true
+  +      encodingType: 1
+  +      foreignKey: {}
+  +      geoConfig: {}
+  +      id: 4
+  +      interleave: {}
+  +      keyColumnDirections:
+  +      - ASC
+  +      keyColumnIds:
+  +      - 1
+  +      keyColumnNames:
+  +      - i
+  +      name: crdb_internal_index_4_name_placeholder
+  +      partitioning: {}
+  +      sharded: {}
+  +      storeColumnIds:
+  +      - 3
+  +      storeColumnNames:
+  +      - k
+  +      unique: true
+  +      useDeletePreservingEncoding: true
+  +      version: 4
+  +    mutationId: 1
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 5
+  -  nextConstraintId: 2
+  +  nextConstraintId: 4
+     nextFamilyId: 1
+  -  nextIndexId: 3
+  +  nextIndexId: 5
+     nextMutationId: 1
+     parentId: 100
+  ...
+       - 3
+       storeColumnNames:
+  -    - j
+  +    - crdb_internal_column_2_name_placeholder
+       - k
+       unique: true
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "1"
+  +  version: "2"
+write *eventpb.AlterTable to event log for descriptor #104: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+checking for feature: ALTER TABLE
+increment telemetry for sql.schema.alter_table
+increment telemetry for sql.schema.alter_table.drop_column
+## StatementPhase stage 1 of 1 with 3 MutationType ops
+upsert descriptor #104
+  ...
+         oid: 20
+         width: 64
+  -  - defaultExpr: 32:::INT8
+  -    id: 3
+  -    name: k
+  -    nullable: true
+  -    onUpdateExpr: 42:::INT8
+  -    type:
+  -      family: IntFamily
+  -      oid: 20
+  -      width: 64
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  ...
+       - i
+       - crdb_internal_column_2_name_placeholder
+  -    - k
+  +    - crdb_internal_column_3_name_placeholder
+       name: primary
+     formatVersion: 3
+     id: 104
+     indexes: []
+  -  modificationTime: {}
+  +  modificationTime:
+  +    wallTime: "1640995200000000001"
+     mutations:
+     - column:
+  ...
+         keyColumnNames:
+         - crdb_internal_column_4_name_placeholder
+  -      - k
+  +      - crdb_internal_column_3_name_placeholder
+         keySuffixColumnIds:
+         - 1
+  ...
+         - 3
+         storeColumnNames:
+  -      - k
+  +      - crdb_internal_column_3_name_placeholder
+         unique: true
+         version: 4
+  ...
+         - 3
+         storeColumnNames:
+  -      - k
+  +      - crdb_internal_column_3_name_placeholder
+         unique: true
+         useDeletePreservingEncoding: true
+  ...
+       mutationId: 1
+       state: DELETE_ONLY
+  +  - column:
+  +      defaultExpr: 32:::INT8
+  +      id: 3
+  +      name: crdb_internal_column_3_name_placeholder
+  +      nullable: true
+  +      onUpdateExpr: 42:::INT8
+  +      type:
+  +        family: IntFamily
+  +        oid: 20
+  +        width: 64
+  +    direction: DROP
+  +    mutationId: 1
+  +    state: DELETE_AND_WRITE_ONLY
+     name: t
+     nextColumnId: 5
+  ...
+       storeColumnNames:
+       - crdb_internal_column_2_name_placeholder
+  -    - k
+  +    - crdb_internal_column_3_name_placeholder
+       unique: true
+       version: 4
+  ...
+# end StatementPhase
+# begin PreCommitPhase
+## PreCommitPhase stage 1 of 1 with 2 MutationType ops
+upsert descriptor #104
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  +  declarativeSchemaChangerState:
+  +    authorization:
+  +      userName: root
+  +    currentStatuses: <redacted>
+  +    jobId: "1"
+  +    relevantStatements:
+  +    - statement:
+  +        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+  +        statement: ALTER TABLE t DROP COLUMN j CASCADE
+  +        statementTag: ALTER TABLE
+  +    - statement:
+  +        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹k› CASCADE
+  +        statement: ALTER TABLE t DROP COLUMN k CASCADE
+  +        statementTag: ALTER TABLE
+  +      statementRank: 1
+  +    revertible: true
+  +    targetRanks: <redacted>
+  +    targets: <redacted>
+     families:
+     - columnIds:
+  ...
+create job #1 (non-cancelable: false): "ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE; ALTER TABLE defaultdb.public.t DROP COLUMN k CASCADE"
+  descriptor IDs: [104]
+# end PreCommitPhase
+commit transaction #1
+notified job registry to adopt jobs: [1]
+# begin PostCommitPhase
+begin transaction #2
+commit transaction #2
+begin transaction #3
+## PostCommitPhase stage 1 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000001"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: DELETE_AND_WRITE_ONLY
+     - column:
+         defaultExpr: 32:::INT8
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "2"
+  +  version: "3"
+update progress of schema change job #1: "PostCommitPhase stage 2 of 7 with 1 BackfillType op pending"
+commit transaction #3
+begin transaction #4
+## PostCommitPhase stage 2 of 7 with 1 BackfillType op
+backfill indexes [3] from index #1 in table #104
+commit transaction #4
+begin transaction #5
+## PostCommitPhase stage 3 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000003"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: BACKFILLING
+  +    state: DELETE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "3"
+  +  version: "4"
+update progress of schema change job #1: "PostCommitPhase stage 4 of 7 with 1 MutationType op pending"
+commit transaction #5
+begin transaction #6
+## PostCommitPhase stage 4 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000005"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_ONLY
+  +    state: MERGING
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "4"
+  +  version: "5"
+update progress of schema change job #1: "PostCommitPhase stage 5 of 7 with 1 BackfillType op pending"
+commit transaction #6
+begin transaction #7
+## PostCommitPhase stage 5 of 7 with 1 BackfillType op
+merge temporary indexes [4] into backfilled indexes [3] in table #104
+commit transaction #7
+begin transaction #8
+## PostCommitPhase stage 6 of 7 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000006"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: MERGING
+  +    state: DELETE_AND_WRITE_ONLY
+     - direction: ADD
+       index:
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "5"
+  +  version: "6"
+update progress of schema change job #1: "PostCommitPhase stage 7 of 7 with 1 ValidationType op pending"
+commit transaction #8
+begin transaction #9
+## PostCommitPhase stage 7 of 7 with 1 ValidationType op
+validate forward indexes [3] in table #104
+commit transaction #9
+begin transaction #10
+## PostCommitNonRevertiblePhase stage 1 of 3 with 19 MutationType ops
+upsert descriptor #104
+  ...
+           statementTag: ALTER TABLE
+         statementRank: 1
+  -    revertible: true
+       targetRanks: <redacted>
+       targets: <redacted>
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000008"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+       direction: DROP
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     - column:
+         computeExpr: crdb_internal_column_2_name_placeholder + 1:::INT8
+  ...
+       direction: DROP
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     - direction: DROP
+       index:
+  ...
+         version: 3
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 2
+  +      constraintId: 3
+         createdExplicitly: true
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 3
+  +      id: 4
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - i
+  -      name: crdb_internal_index_3_name_placeholder
+  +      name: crdb_internal_index_4_name_placeholder
+         partitioning: {}
+         sharded: {}
+  -      storeColumnIds:
+  -      - 3
+  -      storeColumnNames:
+  -      - crdb_internal_column_3_name_placeholder
+  +      storeColumnIds: []
+  +      storeColumnNames: []
+         unique: true
+  +      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  -  - direction: ADD
+  +    state: DELETE_ONLY
+  +  - column:
+  +      defaultExpr: 32:::INT8
+  +      id: 3
+  +      name: crdb_internal_column_3_name_placeholder
+  +      nullable: true
+  +      onUpdateExpr: 42:::INT8
+  +      type:
+  +        family: IntFamily
+  +        oid: 20
+  +        width: 64
+  +    direction: DROP
+  +    mutationId: 1
+  +    state: DELETE_ONLY
+  +  - direction: DROP
+       index:
+  -      constraintId: 3
+  -      createdExplicitly: true
+  +      constraintId: 1
+  +      createdAtNanos: "1640995200000000000"
+         encodingType: 1
+         foreignKey: {}
+         geoConfig: {}
+  -      id: 4
+  +      id: 1
+         interleave: {}
+         keyColumnDirections:
+  ...
+         keyColumnNames:
+         - i
+  -      name: crdb_internal_index_4_name_placeholder
+  +      name: crdb_internal_index_1_name_placeholder
+         partitioning: {}
+         sharded: {}
+         storeColumnIds:
+  +      - 2
+         - 3
+         storeColumnNames:
+  +      - crdb_internal_column_2_name_placeholder
+         - crdb_internal_column_3_name_placeholder
+         unique: true
+  -      useDeletePreservingEncoding: true
+         version: 4
+       mutationId: 1
+       state: DELETE_AND_WRITE_ONLY
+  -  - column:
+  -      defaultExpr: 32:::INT8
+  -      id: 3
+  -      name: crdb_internal_column_3_name_placeholder
+  -      nullable: true
+  -      onUpdateExpr: 42:::INT8
+  -      type:
+  -        family: IntFamily
+  -        oid: 20
+  -        width: 64
+  -    direction: DROP
+  -    mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+     name: t
+     nextColumnId: 5
+  ...
+     parentId: 100
+     primaryIndex:
+  -    constraintId: 1
+  -    createdAtNanos: "1640995200000000000"
+  +    constraintId: 2
+  +    createdExplicitly: true
+       encodingType: 1
+       foreignKey: {}
+       geoConfig: {}
+  -    id: 1
+  +    id: 3
+       interleave: {}
+       keyColumnDirections:
+  ...
+       partitioning: {}
+       sharded: {}
+  -    storeColumnIds:
+  -    - 2
+  -    - 3
+  -    storeColumnNames:
+  -    - crdb_internal_column_2_name_placeholder
+  -    - crdb_internal_column_3_name_placeholder
+  +    storeColumnIds: []
+  +    storeColumnNames: []
+       unique: true
+       version: 4
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "6"
+  +  version: "7"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending"
+set schema change job #1 to non-cancellable
+commit transaction #10
+begin transaction #11
+## PostCommitNonRevertiblePhase stage 2 of 3 with 3 MutationType ops
+upsert descriptor #104
+  ...
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000010"
+  +  modificationTime: {}
+     mutations:
+     - column:
+  ...
+         version: 4
+       mutationId: 1
+  -    state: DELETE_AND_WRITE_ONLY
+  +    state: DELETE_ONLY
+     name: t
+     nextColumnId: 5
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "7"
+  +  version: "8"
+update progress of schema change job #1: "PostCommitNonRevertiblePhase stage 3 of 3 with 12 MutationType ops pending"
+commit transaction #11
+begin transaction #12
+## PostCommitNonRevertiblePhase stage 3 of 3 with 14 MutationType ops
+upsert descriptor #104
+  ...
+     createAsOfTime:
+       wallTime: "1640995200000000000"
+  -  declarativeSchemaChangerState:
+  -    authorization:
+  -      userName: root
+  -    currentStatuses: <redacted>
+  -    jobId: "1"
+  -    relevantStatements:
+  -    - statement:
+  -        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+  -        statement: ALTER TABLE t DROP COLUMN j CASCADE
+  -        statementTag: ALTER TABLE
+  -    - statement:
+  -        redactedStatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹k› CASCADE
+  -        statement: ALTER TABLE t DROP COLUMN k CASCADE
+  -        statementTag: ALTER TABLE
+  -      statementRank: 1
+  -    targetRanks: <redacted>
+  -    targets: <redacted>
+     families:
+     - columnIds:
+       - 1
+  -    - 2
+  -    - 3
+       columnNames:
+       - i
+  -    - crdb_internal_column_2_name_placeholder
+  -    - crdb_internal_column_3_name_placeholder
+       name: primary
+     formatVersion: 3
+     id: 104
+     indexes: []
+  -  modificationTime:
+  -    wallTime: "1640995200000000011"
+  -  mutations:
+  -  - column:
+  -      id: 2
+  -      name: crdb_internal_column_2_name_placeholder
+  -      nullable: true
+  -      type:
+  -        family: IntFamily
+  -        oid: 20
+  -        width: 64
+  -    direction: DROP
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - column:
+  -      computeExpr: crdb_internal_column_2_name_placeholder + 1:::INT8
+  -      id: 4
+  -      inaccessible: true
+  -      name: crdb_internal_column_4_name_placeholder
+  -      nullable: true
+  -      type:
+  -        family: IntFamily
+  -        oid: 20
+  -        width: 64
+  -      virtual: true
+  -    direction: DROP
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      createdAtNanos: "1640995200000000000"
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 2
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      - ASC
+  -      keyColumnIds:
+  -      - 4
+  -      - 3
+  -      keyColumnNames:
+  -      - crdb_internal_column_4_name_placeholder
+  -      - crdb_internal_column_3_name_placeholder
+  -      keySuffixColumnIds:
+  -      - 1
+  -      name: crdb_internal_index_2_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      version: 3
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 3
+  -      createdExplicitly: true
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 4
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - i
+  -      name: crdb_internal_index_4_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnIds: []
+  -      storeColumnNames: []
+  -      unique: true
+  -      useDeletePreservingEncoding: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - column:
+  -      defaultExpr: 32:::INT8
+  -      id: 3
+  -      name: crdb_internal_column_3_name_placeholder
+  -      nullable: true
+  -      onUpdateExpr: 42:::INT8
+  -      type:
+  -        family: IntFamily
+  -        oid: 20
+  -        width: 64
+  -    direction: DROP
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  -  - direction: DROP
+  -    index:
+  -      constraintId: 1
+  -      createdAtNanos: "1640995200000000000"
+  -      encodingType: 1
+  -      foreignKey: {}
+  -      geoConfig: {}
+  -      id: 1
+  -      interleave: {}
+  -      keyColumnDirections:
+  -      - ASC
+  -      keyColumnIds:
+  -      - 1
+  -      keyColumnNames:
+  -      - i
+  -      name: crdb_internal_index_1_name_placeholder
+  -      partitioning: {}
+  -      sharded: {}
+  -      storeColumnIds:
+  -      - 2
+  -      - 3
+  -      storeColumnNames:
+  -      - crdb_internal_column_2_name_placeholder
+  -      - crdb_internal_column_3_name_placeholder
+  -      unique: true
+  -      version: 4
+  -    mutationId: 1
+  -    state: DELETE_ONLY
+  +  modificationTime: {}
+  +  mutations: []
+     name: t
+     nextColumnId: 5
+  ...
+       time: {}
+     unexposedParentSchemaId: 101
+  -  version: "8"
+  +  version: "9"
+write *eventpb.DropIndex to event log for descriptor #104: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+write *eventpb.FinishSchemaChange to event log for descriptor 104
+create job #2 (non-cancelable: true): "GC for ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE"
+  descriptor IDs: [104]
+update progress of schema change job #1: "all stages completed"
+commit transaction #12
+notified job registry to adopt jobs: [2]
+# end PostCommitPhase
diff --git a/pkg/sql/schemachanger/testdata/explain/drop_column_basic b/pkg/sql/schemachanger/testdata/explain/drop_column_basic
new file mode 100644
index 000000000000..2227f4c47c0e
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain/drop_column_basic
@@ -0,0 +1,121 @@
+/* setup */
+create table t (i int primary key, j int);
+
+/* test */
+EXPLAIN (ddl) alter table t drop column j;
+----
+Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›; 
+ ├── StatementPhase
+ │    └── Stage 1 of 1 in StatementPhase
+ │         ├── 2 elements transitioning toward ABSENT
+ │         │    ├── PUBLIC → WRITE_ONLY    Column:{DescID: 104, ColumnID: 2}
+ │         │    └── PUBLIC → ABSENT        ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+ │         ├── 3 elements transitioning toward PUBLIC
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+ │         │    ├── ABSENT → BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │         │    └── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+ │         ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │         │    └── ABSENT → DELETE_ONLY   TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+ │         └── 7 Mutation operations
+ │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":2,"TableID":104}
+ │              ├── LogEvent {"TargetStatus":1}
+ │              ├── SetColumnName {"ColumnID":2,"Name":"crdb_internal_co...","TableID":104}
+ │              ├── MakeAddedIndexBackfilling {"Index":{"ConstraintID":1,"IndexID":2,"IsUnique":true,"SourceIndexID":1,"TableID":104,"TemporaryIndexID":3}}
+ │              ├── MakeAddedTempIndexDeleteOnly {"Index":{"ConstraintID":1,"IndexID":3,"IsUnique":true,"SourceIndexID":1,"TableID":104}}
+ │              ├── AddColumnToIndex {"ColumnID":1,"IndexID":3,"TableID":104}
+ │              └── AddColumnToIndex {"ColumnID":1,"IndexID":2,"TableID":104}
+ ├── PreCommitPhase
+ │    └── Stage 1 of 1 in PreCommitPhase
+ │         └── 2 Mutation operations
+ │              ├── SetJobStateOnDescriptor {"DescriptorID":104,"Initialize":true}
+ │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ ├── PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 2 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILL_ONLY → BACKFILLED PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── BackfillIndex {"IndexID":2,"SourceIndexID":1,"TableID":104}
+ │    ├── Stage 3 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILLED → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":2,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 4 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── DELETE_ONLY → MERGE_ONLY PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":2,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 5 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGE_ONLY → MERGED PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── MergeIndex {"BackfilledIndexID":2,"TableID":104,"TemporaryIndexID":3}
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":2,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
+ │         ├── 1 element transitioning toward PUBLIC
+ │         │    └── WRITE_ONLY → VALIDATED PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+ │         └── 1 Validation operation
+ │              └── ValidateUniqueIndex {"IndexID":2,"TableID":104}
+ └── PostCommitNonRevertiblePhase
+      ├── Stage 1 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 5 elements transitioning toward ABSENT
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    │    └── PUBLIC     → ABSENT                IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+      │    ├── 2 elements transitioning toward PUBLIC
+      │    │    ├── VALIDATED  → PUBLIC                PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+      │    │    └── ABSENT     → PUBLIC                IndexName:{DescID: 104, Name: t_pkey, IndexID: 2}
+      │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+      │    │    └── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+      │    └── 10 Mutation operations
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":2,"TableID":104}
+      │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":104}
+      │         ├── SetIndexName {"IndexID":2,"Name":"t_pkey","TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":3,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":2,"IndexID":1,"Kind":2,"TableID":104}
+      │         ├── MakeAddedPrimaryIndexPublic {"IndexID":2,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      ├── Stage 2 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 1 element transitioning toward ABSENT
+      │    │    └── WRITE_ONLY → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    └── 3 Mutation operations
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      └── Stage 3 of 3 in PostCommitNonRevertiblePhase
+           ├── 3 elements transitioning toward ABSENT
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 2}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+           │    └── DELETE_ONLY           → ABSENT           PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+           ├── 1 element transitioning toward TRANSIENT_ABSENT
+           │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+           └── 7 Mutation operations
+                ├── CreateGcJobForIndex {"IndexID":3,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":3,"TableID":104}
+                ├── CreateGcJobForIndex {"IndexID":1,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":1,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":2,"TableID":104}
+                ├── RemoveJobStateFromDescriptor {"DescriptorID":104}
+                └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"all stages compl..."}
diff --git a/pkg/sql/schemachanger/testdata/explain/drop_column_computed_index b/pkg/sql/schemachanger/testdata/explain/drop_column_computed_index
new file mode 100644
index 000000000000..3f5c6fd428cf
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain/drop_column_computed_index
@@ -0,0 +1,145 @@
+/* setup */
+create table t (i int primary key, j int, index((j+1)));
+
+/* test */
+EXPLAIN (ddl) alter table t drop column j cascade;
+----
+Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE; 
+ ├── StatementPhase
+ │    └── Stage 1 of 1 in StatementPhase
+ │         ├── 6 elements transitioning toward ABSENT
+ │         │    ├── PUBLIC → WRITE_ONLY    Column:{DescID: 104, ColumnID: 2}
+ │         │    ├── PUBLIC → ABSENT        ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+ │         │    ├── PUBLIC → WRITE_ONLY    Column:{DescID: 104, ColumnID: 3}
+ │         │    ├── PUBLIC → ABSENT        ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 3}
+ │         │    ├── PUBLIC → VALIDATED     SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+ │         │    └── PUBLIC → ABSENT        IndexName:{DescID: 104, Name: t_expr_idx, IndexID: 2}
+ │         ├── 3 elements transitioning toward PUBLIC
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+ │         │    ├── ABSENT → BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │         │    └── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+ │         ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │         │    └── ABSENT → DELETE_ONLY   TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+ │         └── 12 Mutation operations
+ │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":2,"TableID":104}
+ │              ├── LogEvent {"TargetStatus":1}
+ │              ├── SetColumnName {"ColumnID":2,"Name":"crdb_internal_co...","TableID":104}
+ │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":3,"TableID":104}
+ │              ├── LogEvent {"TargetStatus":1}
+ │              ├── SetColumnName {"ColumnID":3,"Name":"crdb_internal_co...","TableID":104}
+ │              ├── MakeDroppedNonPrimaryIndexDeleteAndWriteOnly {"IndexID":2,"TableID":104}
+ │              ├── SetIndexName {"IndexID":2,"Name":"crdb_internal_in...","TableID":104}
+ │              ├── MakeAddedIndexBackfilling {"Index":{"ConstraintID":1,"IndexID":3,"IsUnique":true,"SourceIndexID":1,"TableID":104,"TemporaryIndexID":4}}
+ │              ├── MakeAddedTempIndexDeleteOnly {"Index":{"ConstraintID":1,"IndexID":4,"IsUnique":true,"SourceIndexID":1,"TableID":104}}
+ │              ├── AddColumnToIndex {"ColumnID":1,"IndexID":4,"TableID":104}
+ │              └── AddColumnToIndex {"ColumnID":1,"IndexID":3,"TableID":104}
+ ├── PreCommitPhase
+ │    └── Stage 1 of 1 in PreCommitPhase
+ │         └── 2 Mutation operations
+ │              ├── SetJobStateOnDescriptor {"DescriptorID":104,"Initialize":true}
+ │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ ├── PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":4,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 2 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILL_ONLY → BACKFILLED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── BackfillIndex {"IndexID":3,"SourceIndexID":1,"TableID":104}
+ │    ├── Stage 3 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILLED → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 4 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── DELETE_ONLY → MERGE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 5 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGE_ONLY → MERGED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── MergeIndex {"BackfilledIndexID":3,"TableID":104,"TemporaryIndexID":4}
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
+ │         ├── 1 element transitioning toward PUBLIC
+ │         │    └── WRITE_ONLY → VALIDATED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │         └── 1 Validation operation
+ │              └── ValidateUniqueIndex {"IndexID":3,"TableID":104}
+ └── PostCommitNonRevertiblePhase
+      ├── Stage 1 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 9 elements transitioning toward ABSENT
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 2}
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 3}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+      │    │    └── VALIDATED  → DELETE_ONLY           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+      │    ├── 2 elements transitioning toward PUBLIC
+      │    │    ├── VALIDATED  → PUBLIC                PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+      │    │    └── ABSENT     → PUBLIC                IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+      │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+      │    │    └── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+      │    └── 14 Mutation operations
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":2,"TableID":104}
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":3,"TableID":104}
+      │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":104}
+      │         ├── SetIndexName {"IndexID":3,"Name":"t_pkey","TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":4,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":2,"IndexID":1,"Kind":2,"TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":2,"TableID":104}
+      │         ├── MakeAddedPrimaryIndexPublic {"IndexID":3,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":2,"Kind":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      ├── Stage 2 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 1 element transitioning toward ABSENT
+      │    │    └── WRITE_ONLY → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    └── 3 Mutation operations
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      └── Stage 3 of 3 in PostCommitNonRevertiblePhase
+           ├── 6 elements transitioning toward ABSENT
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 2}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 3}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
+           │    ├── DELETE_ONLY           → ABSENT           PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+           │    └── DELETE_ONLY           → ABSENT           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+           ├── 1 element transitioning toward TRANSIENT_ABSENT
+           │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+           └── 11 Mutation operations
+                ├── CreateGcJobForIndex {"IndexID":4,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":4,"TableID":104}
+                ├── CreateGcJobForIndex {"IndexID":1,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":1,"TableID":104}
+                ├── LogEvent {"TargetStatus":1}
+                ├── CreateGcJobForIndex {"IndexID":2,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":2,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":2,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":3,"TableID":104}
+                ├── RemoveJobStateFromDescriptor {"DescriptorID":104}
+                └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"all stages compl..."}
diff --git a/pkg/sql/schemachanger/testdata/explain/drop_column_create_index_separate_statements.0 b/pkg/sql/schemachanger/testdata/explain/drop_column_create_index_separate_statements.0
new file mode 100644
index 000000000000..a37f8c4f8a6f
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain/drop_column_create_index_separate_statements.0
@@ -0,0 +1,153 @@
+/* setup */
+create table t (i int primary key, j int, k int default 32 on update 42, index((j+1), k));
+
+/* test */
+EXPLAIN (ddl) alter table t drop column j cascade;
+----
+Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE; 
+ ├── StatementPhase
+ │    └── Stage 1 of 1 in StatementPhase
+ │         ├── 6 elements transitioning toward ABSENT
+ │         │    ├── PUBLIC → WRITE_ONLY    Column:{DescID: 104, ColumnID: 2}
+ │         │    ├── PUBLIC → ABSENT        ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+ │         │    ├── PUBLIC → WRITE_ONLY    Column:{DescID: 104, ColumnID: 4}
+ │         │    ├── PUBLIC → ABSENT        ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 4}
+ │         │    ├── PUBLIC → VALIDATED     SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+ │         │    └── PUBLIC → ABSENT        IndexName:{DescID: 104, Name: t_expr_k_idx, IndexID: 2}
+ │         ├── 5 elements transitioning toward PUBLIC
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}
+ │         │    ├── ABSENT → BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+ │         │    └── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}
+ │         ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │         │    └── ABSENT → DELETE_ONLY   TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+ │         └── 14 Mutation operations
+ │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":2,"TableID":104}
+ │              ├── LogEvent {"TargetStatus":1}
+ │              ├── SetColumnName {"ColumnID":2,"Name":"crdb_internal_co...","TableID":104}
+ │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":4,"TableID":104}
+ │              ├── LogEvent {"TargetStatus":1}
+ │              ├── SetColumnName {"ColumnID":4,"Name":"crdb_internal_co...","TableID":104}
+ │              ├── MakeDroppedNonPrimaryIndexDeleteAndWriteOnly {"IndexID":2,"TableID":104}
+ │              ├── SetIndexName {"IndexID":2,"Name":"crdb_internal_in...","TableID":104}
+ │              ├── MakeAddedIndexBackfilling {"Index":{"ConstraintID":1,"IndexID":3,"IsUnique":true,"SourceIndexID":1,"TableID":104,"TemporaryIndexID":4}}
+ │              ├── MakeAddedTempIndexDeleteOnly {"Index":{"ConstraintID":1,"IndexID":4,"IsUnique":true,"SourceIndexID":1,"TableID":104}}
+ │              ├── AddColumnToIndex {"ColumnID":1,"IndexID":4,"TableID":104}
+ │              ├── AddColumnToIndex {"ColumnID":3,"IndexID":4,"Kind":2,"TableID":104}
+ │              ├── AddColumnToIndex {"ColumnID":1,"IndexID":3,"TableID":104}
+ │              └── AddColumnToIndex {"ColumnID":3,"IndexID":3,"Kind":2,"TableID":104}
+ ├── PreCommitPhase
+ │    └── Stage 1 of 1 in PreCommitPhase
+ │         └── 2 Mutation operations
+ │              ├── SetJobStateOnDescriptor {"DescriptorID":104,"Initialize":true}
+ │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ ├── PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":4,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 2 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILL_ONLY → BACKFILLED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── BackfillIndex {"IndexID":3,"SourceIndexID":1,"TableID":104}
+ │    ├── Stage 3 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILLED → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 4 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── DELETE_ONLY → MERGE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 5 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGE_ONLY → MERGED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── MergeIndex {"BackfilledIndexID":3,"TableID":104,"TemporaryIndexID":4}
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
+ │         ├── 1 element transitioning toward PUBLIC
+ │         │    └── WRITE_ONLY → VALIDATED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │         └── 1 Validation operation
+ │              └── ValidateUniqueIndex {"IndexID":3,"TableID":104}
+ └── PostCommitNonRevertiblePhase
+      ├── Stage 1 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 11 elements transitioning toward ABSENT
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 2}
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 4}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+      │    │    └── VALIDATED  → DELETE_ONLY           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+      │    ├── 2 elements transitioning toward PUBLIC
+      │    │    ├── VALIDATED  → PUBLIC                PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+      │    │    └── ABSENT     → PUBLIC                IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+      │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+      │    │    └── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+      │    └── 16 Mutation operations
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":2,"TableID":104}
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":4,"TableID":104}
+      │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":104}
+      │         ├── SetIndexName {"IndexID":3,"Name":"t_pkey","TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":4,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":2,"IndexID":1,"Kind":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":1,"Kind":2,"Ordinal":1,"TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":2,"TableID":104}
+      │         ├── MakeAddedPrimaryIndexPublic {"IndexID":3,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":4,"IndexID":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":2,"Ordinal":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":2,"Kind":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      ├── Stage 2 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 1 element transitioning toward ABSENT
+      │    │    └── WRITE_ONLY → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    └── 3 Mutation operations
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      └── Stage 3 of 3 in PostCommitNonRevertiblePhase
+           ├── 6 elements transitioning toward ABSENT
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 2}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 4}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+           │    ├── DELETE_ONLY           → ABSENT           PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+           │    └── DELETE_ONLY           → ABSENT           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+           ├── 1 element transitioning toward TRANSIENT_ABSENT
+           │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+           └── 11 Mutation operations
+                ├── CreateGcJobForIndex {"IndexID":4,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":4,"TableID":104}
+                ├── CreateGcJobForIndex {"IndexID":1,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":1,"TableID":104}
+                ├── LogEvent {"TargetStatus":1}
+                ├── CreateGcJobForIndex {"IndexID":2,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":2,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":2,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":4,"TableID":104}
+                ├── RemoveJobStateFromDescriptor {"DescriptorID":104}
+                └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"all stages compl..."}
diff --git a/pkg/sql/schemachanger/testdata/explain/drop_column_create_index_separate_statements.1 b/pkg/sql/schemachanger/testdata/explain/drop_column_create_index_separate_statements.1
new file mode 100644
index 000000000000..f79049a015aa
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain/drop_column_create_index_separate_statements.1
@@ -0,0 +1,188 @@
+/* setup */
+create table t (i int primary key, j int, k int default 32 on update 42, index((j+1), k));
+
+/* test */
+alter table t drop column j cascade;
+EXPLAIN (ddl) create unique index idx on t(k);
+----
+Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE; CREATE UNIQUE INDEX ‹idx› ON ‹defaultdb›.‹public›.‹t› (‹k›); 
+ ├── PreCommitPhase
+ │    └── Stage 1 of 1 in PreCommitPhase
+ │         └── 2 Mutation operations
+ │              ├── SetJobStateOnDescriptor {"DescriptorID":104,"Initialize":true}
+ │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ ├── PostCommitPhase
+ │    ├── Stage 1 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":4,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 2 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILL_ONLY → BACKFILLED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── BackfillIndex {"IndexID":3,"SourceIndexID":1,"TableID":104}
+ │    ├── Stage 3 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILLED → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 4 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── DELETE_ONLY → MERGE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 5 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGE_ONLY → MERGED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── MergeIndex {"BackfilledIndexID":3,"TableID":104,"TemporaryIndexID":4}
+ │    ├── Stage 6 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 7 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── WRITE_ONLY → VALIDATED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Validation operation
+ │    │         └── ValidateUniqueIndex {"IndexID":3,"TableID":104}
+ │    ├── Stage 8 of 15 in PostCommitPhase
+ │    │    ├── 2 elements transitioning toward ABSENT
+ │    │    │    ├── PUBLIC    → VALIDATED     PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+ │    │    │    └── PUBLIC    → ABSENT        IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+ │    │    ├── 7 elements transitioning toward PUBLIC
+ │    │    │    ├── VALIDATED → PUBLIC        PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    │    ├── ABSENT    → PUBLIC        IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+ │    │    │    ├── ABSENT    → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 5}
+ │    │    │    ├── ABSENT    → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 5}
+ │    │    │    ├── ABSENT    → BACKFILL_ONLY SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+ │    │    │    ├── ABSENT    → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 6}
+ │    │    │    └── ABSENT    → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 6}
+ │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │    │    │    └── ABSENT    → DELETE_ONLY   TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+ │    │    └── 12 Mutation operations
+ │    │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":104}
+ │    │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":104}
+ │    │         ├── SetIndexName {"IndexID":3,"Name":"t_pkey","TableID":104}
+ │    │         ├── MakeAddedPrimaryIndexPublic {"IndexID":3,"TableID":104}
+ │    │         ├── MakeAddedIndexBackfilling {"IsSecondaryIndex":true}
+ │    │         ├── MakeAddedTempIndexDeleteOnly {"IsSecondaryIndex":true}
+ │    │         ├── AddColumnToIndex {"ColumnID":3,"IndexID":6,"TableID":104}
+ │    │         ├── AddColumnToIndex {"ColumnID":1,"IndexID":6,"Kind":1,"TableID":104}
+ │    │         ├── AddColumnToIndex {"ColumnID":3,"IndexID":5,"TableID":104}
+ │    │         ├── AddColumnToIndex {"ColumnID":1,"IndexID":5,"Kind":1,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 9 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":6,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 10 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILL_ONLY → BACKFILLED SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+ │    │    └── 1 Backfill operation
+ │    │         └── BackfillIndex {"IndexID":5,"SourceIndexID":3,"TableID":104}
+ │    ├── Stage 11 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILLED → DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":5,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 12 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── DELETE_ONLY → MERGE_ONLY SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":5,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 13 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGE_ONLY → MERGED SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+ │    │    └── 1 Backfill operation
+ │    │         └── MergeIndex {"BackfilledIndexID":5,"TableID":104,"TemporaryIndexID":6}
+ │    ├── Stage 14 of 15 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":5,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 15 of 15 in PostCommitPhase
+ │         ├── 1 element transitioning toward PUBLIC
+ │         │    └── WRITE_ONLY → VALIDATED SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+ │         └── 1 Validation operation
+ │              └── ValidateUniqueIndex {"IndexID":5,"TableID":104}
+ └── PostCommitNonRevertiblePhase
+      ├── Stage 1 of 2 in PostCommitNonRevertiblePhase
+      │    ├── 10 elements transitioning toward ABSENT
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 2}
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 4}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+      │    │    ├── VALIDATED  → DELETE_ONLY           PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+      │    │    └── VALIDATED  → DELETE_ONLY           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+      │    ├── 2 elements transitioning toward PUBLIC
+      │    │    ├── VALIDATED  → PUBLIC                SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+      │    │    └── ABSENT     → PUBLIC                IndexName:{DescID: 104, Name: idx, IndexID: 5}
+      │    ├── 2 elements transitioning toward TRANSIENT_ABSENT
+      │    │    ├── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+      │    │    └── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+      │    └── 16 Mutation operations
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":2,"TableID":104}
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":4,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":2,"IndexID":1,"Kind":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":1,"Kind":2,"Ordinal":1,"TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":4,"TableID":104}
+      │         ├── SetIndexName {"IndexID":5,"Name":"idx","TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":6,"TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":1,"TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":2,"TableID":104}
+      │         ├── MakeAddedSecondaryIndexPublic {"IndexID":5,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":4,"IndexID":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":2,"Ordinal":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":2,"Kind":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      └── Stage 2 of 2 in PostCommitNonRevertiblePhase
+           ├── 6 elements transitioning toward ABSENT
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 2}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 4}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+           │    ├── DELETE_ONLY           → ABSENT           PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+           │    └── DELETE_ONLY           → ABSENT           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+           ├── 2 elements transitioning toward TRANSIENT_ABSENT
+           │    ├── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+           │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+           └── 13 Mutation operations
+                ├── CreateGcJobForIndex {"IndexID":4,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":4,"TableID":104}
+                ├── CreateGcJobForIndex {"IndexID":6,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":6,"TableID":104}
+                ├── CreateGcJobForIndex {"IndexID":1,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":1,"TableID":104}
+                ├── LogEvent {"TargetStatus":1}
+                ├── CreateGcJobForIndex {"IndexID":2,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":2,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":2,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":4,"TableID":104}
+                ├── RemoveJobStateFromDescriptor {"DescriptorID":104}
+                └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"all stages compl..."}
diff --git a/pkg/sql/schemachanger/testdata/explain/drop_column_unique_index b/pkg/sql/schemachanger/testdata/explain/drop_column_unique_index
new file mode 100644
index 000000000000..882fe4f30d0b
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain/drop_column_unique_index
@@ -0,0 +1,138 @@
+/* setup */
+CREATE DATABASE t;
+CREATE TABLE t.test (k INT PRIMARY KEY, v INT, pi DECIMAL DEFAULT (DECIMAL '3.14'));
+CREATE UNIQUE INDEX vidx ON t.test (v);
+ALTER TABLE t.test ADD COLUMN x DECIMAL DEFAULT (DECIMAL '1.4') CHECK (x >= 0);
+
+/* test */
+EXPLAIN (ddl) ALTER TABLE t.test DROP pi;
+----
+Schema change plan for ALTER TABLE ‹t›.‹public›.‹test› DROP COLUMN ‹pi›; 
+ ├── StatementPhase
+ │    └── Stage 1 of 1 in StatementPhase
+ │         ├── 2 elements transitioning toward ABSENT
+ │         │    ├── PUBLIC → WRITE_ONLY    Column:{DescID: 106, ColumnID: 3}
+ │         │    └── PUBLIC → ABSENT        ColumnName:{DescID: 106, Name: pi, ColumnID: 3}
+ │         ├── 7 elements transitioning toward PUBLIC
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 4}
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 4}
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 106, ColumnID: 4, IndexID: 4}
+ │         │    ├── ABSENT → BACKFILL_ONLY PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 5}
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 5}
+ │         │    └── ABSENT → PUBLIC        IndexColumn:{DescID: 106, ColumnID: 4, IndexID: 5}
+ │         ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │         │    └── ABSENT → DELETE_ONLY   TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+ │         └── 11 Mutation operations
+ │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":3,"TableID":106}
+ │              ├── LogEvent {"TargetStatus":1}
+ │              ├── SetColumnName {"ColumnID":3,"Name":"crdb_internal_co...","TableID":106}
+ │              ├── MakeAddedIndexBackfilling {"Index":{"ConstraintID":1,"IndexID":4,"IsUnique":true,"SourceIndexID":1,"TableID":106,"TemporaryIndexID":5}}
+ │              ├── MakeAddedTempIndexDeleteOnly {"Index":{"ConstraintID":1,"IndexID":5,"IsUnique":true,"SourceIndexID":1,"TableID":106}}
+ │              ├── AddColumnToIndex {"ColumnID":1,"IndexID":5,"TableID":106}
+ │              ├── AddColumnToIndex {"ColumnID":2,"IndexID":5,"Kind":2,"TableID":106}
+ │              ├── AddColumnToIndex {"ColumnID":4,"IndexID":5,"Kind":2,"Ordinal":1,"TableID":106}
+ │              ├── AddColumnToIndex {"ColumnID":1,"IndexID":4,"TableID":106}
+ │              ├── AddColumnToIndex {"ColumnID":2,"IndexID":4,"Kind":2,"TableID":106}
+ │              └── AddColumnToIndex {"ColumnID":4,"IndexID":4,"Kind":2,"Ordinal":1,"TableID":106}
+ ├── PreCommitPhase
+ │    └── Stage 1 of 1 in PreCommitPhase
+ │         └── 2 Mutation operations
+ │              ├── SetJobStateOnDescriptor {"DescriptorID":106,"Initialize":true}
+ │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ ├── PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":5,"TableID":106}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 2 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILL_ONLY → BACKFILLED PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── BackfillIndex {"IndexID":4,"SourceIndexID":1,"TableID":106}
+ │    ├── Stage 3 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILLED → DELETE_ONLY PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":4,"TableID":106}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 4 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── DELETE_ONLY → MERGE_ONLY PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":4,"TableID":106}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 5 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGE_ONLY → MERGED PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── MergeIndex {"BackfilledIndexID":4,"TableID":106,"TemporaryIndexID":5}
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":4,"TableID":106}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
+ │         ├── 1 element transitioning toward PUBLIC
+ │         │    └── WRITE_ONLY → VALIDATED PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+ │         └── 1 Validation operation
+ │              └── ValidateUniqueIndex {"IndexID":4,"TableID":106}
+ └── PostCommitNonRevertiblePhase
+      ├── Stage 1 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 7 elements transitioning toward ABSENT
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 106, ColumnID: 3}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 106, ColumnID: 3, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 106, ColumnID: 4, IndexID: 1}
+      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+      │    │    └── PUBLIC     → ABSENT                IndexName:{DescID: 106, Name: test_pkey, IndexID: 1}
+      │    ├── 2 elements transitioning toward PUBLIC
+      │    │    ├── VALIDATED  → PUBLIC                PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+      │    │    └── ABSENT     → PUBLIC                IndexName:{DescID: 106, Name: test_pkey, IndexID: 4}
+      │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+      │    │    └── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+      │    └── 12 Mutation operations
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":3,"TableID":106}
+      │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":106}
+      │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":106}
+      │         ├── SetIndexName {"IndexID":4,"Name":"test_pkey","TableID":106}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":5,"TableID":106}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":1,"TableID":106}
+      │         ├── RemoveColumnFromIndex {"ColumnID":2,"IndexID":1,"Kind":2,"TableID":106}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":1,"Kind":2,"Ordinal":1,"TableID":106}
+      │         ├── RemoveColumnFromIndex {"ColumnID":4,"IndexID":1,"Kind":2,"Ordinal":2,"TableID":106}
+      │         ├── MakeAddedPrimaryIndexPublic {"IndexID":4,"TableID":106}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      ├── Stage 2 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 1 element transitioning toward ABSENT
+      │    │    └── WRITE_ONLY → DELETE_ONLY PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+      │    └── 3 Mutation operations
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":1,"TableID":106}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":106}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      └── Stage 3 of 3 in PostCommitNonRevertiblePhase
+           ├── 4 elements transitioning toward ABSENT
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 106, ColumnID: 3}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 106, ColumnFamilyID: 0, ColumnID: 3}
+           │    ├── PUBLIC                → ABSENT           ColumnDefaultExpression:{DescID: 106, ColumnID: 3}
+           │    └── DELETE_ONLY           → ABSENT           PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+           ├── 1 element transitioning toward TRANSIENT_ABSENT
+           │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+           └── 8 Mutation operations
+                ├── CreateGcJobForIndex {"IndexID":5,"TableID":106}
+                ├── MakeIndexAbsent {"IndexID":5,"TableID":106}
+                ├── CreateGcJobForIndex {"IndexID":1,"TableID":106}
+                ├── MakeIndexAbsent {"IndexID":1,"TableID":106}
+                ├── RemoveColumnDefaultExpression {"ColumnID":3,"TableID":106}
+                ├── MakeColumnAbsent {"ColumnID":3,"TableID":106}
+                ├── RemoveJobStateFromDescriptor {"DescriptorID":106}
+                └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"all stages compl..."}
diff --git a/pkg/sql/schemachanger/testdata/explain/drop_column_with_index b/pkg/sql/schemachanger/testdata/explain/drop_column_with_index
new file mode 100644
index 000000000000..251a74bb5ca8
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain/drop_column_with_index
@@ -0,0 +1,135 @@
+/* setup */
+create table t (i int primary key, j int, index (j));
+
+/* test */
+EXPLAIN (ddl) alter table t drop column j;
+----
+Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›; 
+ ├── StatementPhase
+ │    └── Stage 1 of 1 in StatementPhase
+ │         ├── 4 elements transitioning toward ABSENT
+ │         │    ├── PUBLIC → WRITE_ONLY    Column:{DescID: 104, ColumnID: 2}
+ │         │    ├── PUBLIC → ABSENT        ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+ │         │    ├── PUBLIC → VALIDATED     SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+ │         │    └── PUBLIC → ABSENT        IndexName:{DescID: 104, Name: t_j_idx, IndexID: 2}
+ │         ├── 3 elements transitioning toward PUBLIC
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+ │         │    ├── ABSENT → BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │         │    └── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+ │         ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │         │    └── ABSENT → DELETE_ONLY   TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+ │         └── 9 Mutation operations
+ │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":2,"TableID":104}
+ │              ├── LogEvent {"TargetStatus":1}
+ │              ├── SetColumnName {"ColumnID":2,"Name":"crdb_internal_co...","TableID":104}
+ │              ├── MakeDroppedNonPrimaryIndexDeleteAndWriteOnly {"IndexID":2,"TableID":104}
+ │              ├── SetIndexName {"IndexID":2,"Name":"crdb_internal_in...","TableID":104}
+ │              ├── MakeAddedIndexBackfilling {"Index":{"ConstraintID":1,"IndexID":3,"IsUnique":true,"SourceIndexID":1,"TableID":104,"TemporaryIndexID":4}}
+ │              ├── MakeAddedTempIndexDeleteOnly {"Index":{"ConstraintID":1,"IndexID":4,"IsUnique":true,"SourceIndexID":1,"TableID":104}}
+ │              ├── AddColumnToIndex {"ColumnID":1,"IndexID":4,"TableID":104}
+ │              └── AddColumnToIndex {"ColumnID":1,"IndexID":3,"TableID":104}
+ ├── PreCommitPhase
+ │    └── Stage 1 of 1 in PreCommitPhase
+ │         └── 2 Mutation operations
+ │              ├── SetJobStateOnDescriptor {"DescriptorID":104,"Initialize":true}
+ │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ ├── PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":4,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 2 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILL_ONLY → BACKFILLED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── BackfillIndex {"IndexID":3,"SourceIndexID":1,"TableID":104}
+ │    ├── Stage 3 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILLED → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 4 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── DELETE_ONLY → MERGE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 5 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGE_ONLY → MERGED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── MergeIndex {"BackfilledIndexID":3,"TableID":104,"TemporaryIndexID":4}
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
+ │         ├── 1 element transitioning toward PUBLIC
+ │         │    └── WRITE_ONLY → VALIDATED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │         └── 1 Validation operation
+ │              └── ValidateUniqueIndex {"IndexID":3,"TableID":104}
+ └── PostCommitNonRevertiblePhase
+      ├── Stage 1 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 8 elements transitioning toward ABSENT
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+      │    │    └── VALIDATED  → DELETE_ONLY           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+      │    ├── 2 elements transitioning toward PUBLIC
+      │    │    ├── VALIDATED  → PUBLIC                PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+      │    │    └── ABSENT     → PUBLIC                IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+      │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+      │    │    └── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+      │    └── 13 Mutation operations
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":2,"TableID":104}
+      │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":104}
+      │         ├── SetIndexName {"IndexID":3,"Name":"t_pkey","TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":4,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":2,"IndexID":1,"Kind":2,"TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":2,"TableID":104}
+      │         ├── MakeAddedPrimaryIndexPublic {"IndexID":3,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":2,"IndexID":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":2,"Kind":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      ├── Stage 2 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 1 element transitioning toward ABSENT
+      │    │    └── WRITE_ONLY → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    └── 3 Mutation operations
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      └── Stage 3 of 3 in PostCommitNonRevertiblePhase
+           ├── 4 elements transitioning toward ABSENT
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 2}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+           │    ├── DELETE_ONLY           → ABSENT           PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+           │    └── DELETE_ONLY           → ABSENT           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+           ├── 1 element transitioning toward TRANSIENT_ABSENT
+           │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+           └── 10 Mutation operations
+                ├── CreateGcJobForIndex {"IndexID":4,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":4,"TableID":104}
+                ├── CreateGcJobForIndex {"IndexID":1,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":1,"TableID":104}
+                ├── LogEvent {"TargetStatus":1}
+                ├── CreateGcJobForIndex {"IndexID":2,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":2,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":2,"TableID":104}
+                ├── RemoveJobStateFromDescriptor {"DescriptorID":104}
+                └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"all stages compl..."}
diff --git a/pkg/sql/schemachanger/testdata/explain/drop_multiple_columns_separate_statements.0 b/pkg/sql/schemachanger/testdata/explain/drop_multiple_columns_separate_statements.0
new file mode 100644
index 000000000000..a37f8c4f8a6f
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain/drop_multiple_columns_separate_statements.0
@@ -0,0 +1,153 @@
+/* setup */
+create table t (i int primary key, j int, k int default 32 on update 42, index((j+1), k));
+
+/* test */
+EXPLAIN (ddl) alter table t drop column j cascade;
+----
+Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE; 
+ ├── StatementPhase
+ │    └── Stage 1 of 1 in StatementPhase
+ │         ├── 6 elements transitioning toward ABSENT
+ │         │    ├── PUBLIC → WRITE_ONLY    Column:{DescID: 104, ColumnID: 2}
+ │         │    ├── PUBLIC → ABSENT        ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+ │         │    ├── PUBLIC → WRITE_ONLY    Column:{DescID: 104, ColumnID: 4}
+ │         │    ├── PUBLIC → ABSENT        ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 4}
+ │         │    ├── PUBLIC → VALIDATED     SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+ │         │    └── PUBLIC → ABSENT        IndexName:{DescID: 104, Name: t_expr_k_idx, IndexID: 2}
+ │         ├── 5 elements transitioning toward PUBLIC
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}
+ │         │    ├── ABSENT → BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+ │         │    └── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}
+ │         ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │         │    └── ABSENT → DELETE_ONLY   TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+ │         └── 14 Mutation operations
+ │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":2,"TableID":104}
+ │              ├── LogEvent {"TargetStatus":1}
+ │              ├── SetColumnName {"ColumnID":2,"Name":"crdb_internal_co...","TableID":104}
+ │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":4,"TableID":104}
+ │              ├── LogEvent {"TargetStatus":1}
+ │              ├── SetColumnName {"ColumnID":4,"Name":"crdb_internal_co...","TableID":104}
+ │              ├── MakeDroppedNonPrimaryIndexDeleteAndWriteOnly {"IndexID":2,"TableID":104}
+ │              ├── SetIndexName {"IndexID":2,"Name":"crdb_internal_in...","TableID":104}
+ │              ├── MakeAddedIndexBackfilling {"Index":{"ConstraintID":1,"IndexID":3,"IsUnique":true,"SourceIndexID":1,"TableID":104,"TemporaryIndexID":4}}
+ │              ├── MakeAddedTempIndexDeleteOnly {"Index":{"ConstraintID":1,"IndexID":4,"IsUnique":true,"SourceIndexID":1,"TableID":104}}
+ │              ├── AddColumnToIndex {"ColumnID":1,"IndexID":4,"TableID":104}
+ │              ├── AddColumnToIndex {"ColumnID":3,"IndexID":4,"Kind":2,"TableID":104}
+ │              ├── AddColumnToIndex {"ColumnID":1,"IndexID":3,"TableID":104}
+ │              └── AddColumnToIndex {"ColumnID":3,"IndexID":3,"Kind":2,"TableID":104}
+ ├── PreCommitPhase
+ │    └── Stage 1 of 1 in PreCommitPhase
+ │         └── 2 Mutation operations
+ │              ├── SetJobStateOnDescriptor {"DescriptorID":104,"Initialize":true}
+ │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ ├── PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":4,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 2 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILL_ONLY → BACKFILLED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── BackfillIndex {"IndexID":3,"SourceIndexID":1,"TableID":104}
+ │    ├── Stage 3 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILLED → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 4 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── DELETE_ONLY → MERGE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 5 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGE_ONLY → MERGED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── MergeIndex {"BackfilledIndexID":3,"TableID":104,"TemporaryIndexID":4}
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
+ │         ├── 1 element transitioning toward PUBLIC
+ │         │    └── WRITE_ONLY → VALIDATED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │         └── 1 Validation operation
+ │              └── ValidateUniqueIndex {"IndexID":3,"TableID":104}
+ └── PostCommitNonRevertiblePhase
+      ├── Stage 1 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 11 elements transitioning toward ABSENT
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 2}
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 4}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+      │    │    └── VALIDATED  → DELETE_ONLY           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+      │    ├── 2 elements transitioning toward PUBLIC
+      │    │    ├── VALIDATED  → PUBLIC                PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+      │    │    └── ABSENT     → PUBLIC                IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+      │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+      │    │    └── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+      │    └── 16 Mutation operations
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":2,"TableID":104}
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":4,"TableID":104}
+      │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":104}
+      │         ├── SetIndexName {"IndexID":3,"Name":"t_pkey","TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":4,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":2,"IndexID":1,"Kind":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":1,"Kind":2,"Ordinal":1,"TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":2,"TableID":104}
+      │         ├── MakeAddedPrimaryIndexPublic {"IndexID":3,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":4,"IndexID":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":2,"Ordinal":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":2,"Kind":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      ├── Stage 2 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 1 element transitioning toward ABSENT
+      │    │    └── WRITE_ONLY → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    └── 3 Mutation operations
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      └── Stage 3 of 3 in PostCommitNonRevertiblePhase
+           ├── 6 elements transitioning toward ABSENT
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 2}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 4}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+           │    ├── DELETE_ONLY           → ABSENT           PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+           │    └── DELETE_ONLY           → ABSENT           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+           ├── 1 element transitioning toward TRANSIENT_ABSENT
+           │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+           └── 11 Mutation operations
+                ├── CreateGcJobForIndex {"IndexID":4,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":4,"TableID":104}
+                ├── CreateGcJobForIndex {"IndexID":1,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":1,"TableID":104}
+                ├── LogEvent {"TargetStatus":1}
+                ├── CreateGcJobForIndex {"IndexID":2,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":2,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":2,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":4,"TableID":104}
+                ├── RemoveJobStateFromDescriptor {"DescriptorID":104}
+                └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"all stages compl..."}
diff --git a/pkg/sql/schemachanger/testdata/explain/drop_multiple_columns_separate_statements.1 b/pkg/sql/schemachanger/testdata/explain/drop_multiple_columns_separate_statements.1
new file mode 100644
index 000000000000..bc7c5fcee7a2
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain/drop_multiple_columns_separate_statements.1
@@ -0,0 +1,144 @@
+/* setup */
+create table t (i int primary key, j int, k int default 32 on update 42, index((j+1), k));
+
+/* test */
+alter table t drop column j cascade;
+EXPLAIN (ddl) alter table t drop column k cascade;
+----
+Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE; ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹k› CASCADE; 
+ ├── StatementPhase
+ │    └── Stage 1 of 1 in StatementPhase
+ │         ├── 2 elements transitioning toward ABSENT
+ │         │    ├── PUBLIC → WRITE_ONLY Column:{DescID: 104, ColumnID: 3}
+ │         │    └── PUBLIC → ABSENT     ColumnName:{DescID: 104, Name: k, ColumnID: 3}
+ │         └── 3 Mutation operations
+ │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":3,"TableID":104}
+ │              ├── LogEvent {"TargetStatus":1}
+ │              └── SetColumnName {"ColumnID":3,"Name":"crdb_internal_co...","TableID":104}
+ ├── PreCommitPhase
+ │    └── Stage 1 of 1 in PreCommitPhase
+ │         └── 2 Mutation operations
+ │              ├── SetJobStateOnDescriptor {"DescriptorID":104,"Initialize":true}
+ │              └── CreateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ ├── PostCommitPhase
+ │    ├── Stage 1 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+ │    │    │    └── DELETE_ONLY → WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeAddedIndexDeleteAndWriteOnly {"IndexID":4,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 2 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILL_ONLY → BACKFILLED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── BackfillIndex {"IndexID":3,"SourceIndexID":1,"TableID":104}
+ │    ├── Stage 3 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── BACKFILLED → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfillingIndexDeleteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 4 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── DELETE_ONLY → MERGE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeBackfilledIndexMerging {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    ├── Stage 5 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGE_ONLY → MERGED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 1 Backfill operation
+ │    │         └── MergeIndex {"BackfilledIndexID":3,"TableID":104,"TemporaryIndexID":4}
+ │    ├── Stage 6 of 7 in PostCommitPhase
+ │    │    ├── 1 element transitioning toward PUBLIC
+ │    │    │    └── MERGED → WRITE_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │    │    └── 3 Mutation operations
+ │    │         ├── MakeMergedIndexWriteOnly {"IndexID":3,"TableID":104}
+ │    │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+ │    │         └── UpdateSchemaChangerJob {"RunningStatus":"PostCommitPhase ..."}
+ │    └── Stage 7 of 7 in PostCommitPhase
+ │         ├── 1 element transitioning toward PUBLIC
+ │         │    └── WRITE_ONLY → VALIDATED PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+ │         └── 1 Validation operation
+ │              └── ValidateUniqueIndex {"IndexID":3,"TableID":104}
+ └── PostCommitNonRevertiblePhase
+      ├── Stage 1 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 14 elements transitioning toward ABSENT
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 3}
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 2}
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 4}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+      │    │    ├── VALIDATED  → DELETE_ONLY           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}
+      │    │    └── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}
+      │    ├── 2 elements transitioning toward PUBLIC
+      │    │    ├── VALIDATED  → PUBLIC                PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+      │    │    └── ABSENT     → PUBLIC                IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+      │    ├── 1 element transitioning toward TRANSIENT_ABSENT
+      │    │    └── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+      │    └── 19 Mutation operations
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":3,"TableID":104}
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":2,"TableID":104}
+      │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":4,"TableID":104}
+      │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":3,"Kind":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":4,"Kind":2,"TableID":104}
+      │         ├── SetIndexName {"IndexID":3,"Name":"t_pkey","TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":4,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":2,"IndexID":1,"Kind":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":1,"Kind":2,"Ordinal":1,"TableID":104}
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":2,"TableID":104}
+      │         ├── MakeAddedPrimaryIndexPublic {"IndexID":3,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":4,"IndexID":2,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":3,"IndexID":2,"Ordinal":1,"TableID":104}
+      │         ├── RemoveColumnFromIndex {"ColumnID":1,"IndexID":2,"Kind":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      ├── Stage 2 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 1 element transitioning toward ABSENT
+      │    │    └── WRITE_ONLY → DELETE_ONLY PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    └── 3 Mutation operations
+      │         ├── MakeDroppedIndexDeleteOnly {"IndexID":1,"TableID":104}
+      │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
+      │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
+      └── Stage 3 of 3 in PostCommitNonRevertiblePhase
+           ├── 10 elements transitioning toward ABSENT
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 3}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
+           │    ├── PUBLIC                → ABSENT           ColumnDefaultExpression:{DescID: 104, ColumnID: 3}
+           │    ├── PUBLIC                → ABSENT           ColumnOnUpdateExpression:{DescID: 104, ColumnID: 3}
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 2}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+           │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 4}
+           │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+           │    ├── DELETE_ONLY           → ABSENT           PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+           │    └── DELETE_ONLY           → ABSENT           SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+           ├── 1 element transitioning toward TRANSIENT_ABSENT
+           │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+           └── 14 Mutation operations
+                ├── CreateGcJobForIndex {"IndexID":4,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":4,"TableID":104}
+                ├── CreateGcJobForIndex {"IndexID":1,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":1,"TableID":104}
+                ├── LogEvent {"TargetStatus":1}
+                ├── CreateGcJobForIndex {"IndexID":2,"TableID":104}
+                ├── MakeIndexAbsent {"IndexID":2,"TableID":104}
+                ├── RemoveColumnDefaultExpression {"ColumnID":3,"TableID":104}
+                ├── RemoveColumnOnUpdateExpression {"ColumnID":3,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":2,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":4,"TableID":104}
+                ├── MakeColumnAbsent {"ColumnID":3,"TableID":104}
+                ├── RemoveJobStateFromDescriptor {"DescriptorID":104}
+                └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"all stages compl..."}
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_basic b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_basic
new file mode 100644
index 000000000000..3d48e69ccee3
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_basic
@@ -0,0 +1,473 @@
+/* setup */
+create table t (i int primary key, j int);
+
+/* test */
+EXPLAIN (ddl, verbose) alter table t drop column j;
+----
+• Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›; 
+│
+├── • StatementPhase
+│   │
+│   └── • Stage 1 of 1 in StatementPhase
+│       │
+│       ├── • 2 elements transitioning toward ABSENT
+│       │   │
+│       │   ├── • Column:{DescID: 104, ColumnID: 2}
+│       │   │     PUBLIC → WRITE_ONLY
+│       │   │
+│       │   └── • ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+│       │       │ PUBLIC → ABSENT
+│       │       │
+│       │       └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+│       │             rule: "column dependents removed after column no longer public"
+│       │
+│       ├── • 3 elements transitioning toward PUBLIC
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+│       │   │         rule: "index-column added to index after index exists"
+│       │   │
+│       │   ├── • PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+│       │   │     ABSENT → BACKFILL_ONLY
+│       │   │
+│       │   └── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│       │       │ ABSENT → PUBLIC
+│       │       │
+│       │       └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+│       │             rule: "temp index exists before columns, partitioning, and partial"
+│       │             rule: "index-column added to index after temp index exists"
+│       │
+│       ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│       │   │
+│       │   └── • TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+│       │         ABSENT → DELETE_ONLY
+│       │
+│       └── • 7 Mutation operations
+│           │
+│           ├── • MakeDroppedColumnDeleteAndWriteOnly
+│           │     ColumnID: 2
+│           │     TableID: 104
+│           │
+│           ├── • LogEvent
+│           │     Element:
+│           │       Column:
+│           │         columnId: 2
+│           │         pgAttributeNum: 2
+│           │         tableId: 104
+│           │     EventBase:
+│           │       Authorization:
+│           │         UserName: root
+│           │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+│           │       StatementTag: ALTER TABLE
+│           │       TargetMetadata:
+│           │         SourceElementID: 1
+│           │         SubWorkID: 1
+│           │     TargetStatus: 1
+│           │
+│           ├── • SetColumnName
+│           │     ColumnID: 2
+│           │     Name: crdb_internal_column_2_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeAddedIndexBackfilling
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 2
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 104
+│           │       TemporaryIndexID: 3
+│           │
+│           ├── • MakeAddedTempIndexDeleteOnly
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 3
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 104
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 1
+│           │     IndexID: 3
+│           │     TableID: 104
+│           │
+│           └── • AddColumnToIndex
+│                 ColumnID: 1
+│                 IndexID: 2
+│                 TableID: 104
+│
+├── • PreCommitPhase
+│   │
+│   └── • Stage 1 of 1 in PreCommitPhase
+│       │
+│       └── • 2 Mutation operations
+│           │
+│           ├── • SetJobStateOnDescriptor
+│           │     DescriptorID: 104
+│           │     Initialize: true
+│           │
+│           └── • CreateSchemaChangerJob
+│                 Authorization:
+│                   UserName: root
+│                 DescriptorIDs:
+│                 - 104
+│                 JobID: 1
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
+│                 Statements:
+│                 - statement: ALTER TABLE t DROP COLUMN j
+│                   redactedstatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+│                   statementtag: ALTER TABLE
+│
+├── • PostCommitPhase
+│   │
+│   ├── • Stage 1 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│   │   │   │
+│   │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+│   │   │       │ DELETE_ONLY → WRITE_ONLY
+│   │   │       │
+│   │   │       └── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│   │   │             rule: "index-column added to index before temp index receives writes"
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 2 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+│   │   │       │ BACKFILL_ONLY → BACKFILLED
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       └── • Precedence dependency from WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+│   │   │             rule: "temp index is WRITE_ONLY before backfill"
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • BackfillIndex
+│   │             IndexID: 2
+│   │             SourceIndexID: 1
+│   │             TableID: 104
+│   │
+│   ├── • Stage 3 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+│   │   │         BACKFILLED → DELETE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfillingIndexDeleteOnly
+│   │       │     IndexID: 2
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
+│   │
+│   ├── • Stage 4 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+│   │   │         DELETE_ONLY → MERGE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfilledIndexMerging
+│   │       │     IndexID: 2
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 5 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+│   │   │         MERGE_ONLY → MERGED
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • MergeIndex
+│   │             BackfilledIndexID: 2
+│   │             TableID: 104
+│   │             TemporaryIndexID: 3
+│   │
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 2
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
+│       │
+│       ├── • 1 element transitioning toward PUBLIC
+│       │   │
+│       │   └── • PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+│       │         WRITE_ONLY → VALIDATED
+│       │
+│       └── • 1 Validation operation
+│           │
+│           └── • ValidateUniqueIndex
+│                 IndexID: 2
+│                 TableID: 104
+│
+└── • PostCommitNonRevertiblePhase
+    │
+    ├── • Stage 1 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 5 elements transitioning toward ABSENT
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 2}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │     PUBLIC → WRITE_ONLY
+    │   │   │
+    │   │   └── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+    │   │       │ PUBLIC → ABSENT
+    │   │       │
+    │   │       └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │             rule: "index no longer public before dependents removed"
+    │   │
+    │   ├── • 2 elements transitioning toward PUBLIC
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+    │   │   │   │ VALIDATED → PUBLIC
+    │   │   │   │
+    │   │   │   ├── • SameStagePrecedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │   │     rule: "primary index swap"
+    │   │   │   │
+    │   │   │   └── • SameStagePrecedence dependency from PUBLIC IndexName:{DescID: 104, Name: t_pkey, IndexID: 2}
+    │   │   │         rule: "index named right before index becomes public"
+    │   │   │
+    │   │   └── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 2}
+    │   │       │ ABSENT → PUBLIC
+    │   │       │
+    │   │       └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 1, TemporaryIndexID: 3, SourceIndexID: 1}
+    │   │             rule: "index existence precedes index name and comment"
+    │   │
+    │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+    │   │   │
+    │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+    │   │         WRITE_ONLY → TRANSIENT_DELETE_ONLY
+    │   │
+    │   └── • 10 Mutation operations
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedPrimaryIndexDeleteAndWriteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 1
+    │       │     Name: crdb_internal_index_1_name_placeholder
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 2
+    │       │     Name: t_pkey
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 3
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 2
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeAddedPrimaryIndexPublic
+    │       │     EventBase:
+    │       │       Authorization:
+    │       │         UserName: root
+    │       │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+    │       │       StatementTag: ALTER TABLE
+    │       │       TargetMetadata:
+    │       │         SourceElementID: 1
+    │       │         SubWorkID: 1
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending
+    │
+    ├── • Stage 2 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 1 element transitioning toward ABSENT
+    │   │   │
+    │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │         WRITE_ONLY → DELETE_ONLY
+    │   │
+    │   └── • 3 Mutation operations
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 3 of 3 with 5 MutationType ops pending
+    │
+    └── • Stage 3 of 3 in PostCommitNonRevertiblePhase
+        │
+        ├── • 3 elements transitioning toward ABSENT
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 2}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │         rule: "indexes containing columns reach absent before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   └── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │       │ DELETE_ONLY → ABSENT
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+        │             rule: "temp indexes reach absent at the same time as other indexes"
+        │
+        ├── • 1 element transitioning toward TRANSIENT_ABSENT
+        │   │
+        │   └── • TemporaryIndex:{DescID: 104, IndexID: 3, SourceIndexID: 1}
+        │         TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT
+        │
+        └── • 7 Mutation operations
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 3
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 3
+            │     TableID: 104
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 1
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     IndexID: 1
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 2
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • RemoveJobStateFromDescriptor
+            │     DescriptorID: 104
+            │     JobID: 1
+            │
+            └── • UpdateSchemaChangerJob
+                  IsNonCancelable: true
+                  JobID: 1
+                  RunningStatus: all stages completed
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_computed_index b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_computed_index
new file mode 100644
index 000000000000..7d9223976b67
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_computed_index
@@ -0,0 +1,642 @@
+/* setup */
+create table t (i int primary key, j int, index((j+1)));
+
+/* test */
+EXPLAIN (ddl, verbose) alter table t drop column j cascade;
+----
+• Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE; 
+│
+├── • StatementPhase
+│   │
+│   └── • Stage 1 of 1 in StatementPhase
+│       │
+│       ├── • 6 elements transitioning toward ABSENT
+│       │   │
+│       │   ├── • Column:{DescID: 104, ColumnID: 2}
+│       │   │     PUBLIC → WRITE_ONLY
+│       │   │
+│       │   ├── • ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+│       │   │   │ PUBLIC → ABSENT
+│       │   │   │
+│       │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+│       │   │         rule: "column dependents removed after column no longer public"
+│       │   │
+│       │   ├── • Column:{DescID: 104, ColumnID: 3}
+│       │   │     PUBLIC → WRITE_ONLY
+│       │   │
+│       │   ├── • ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 3}
+│       │   │   │ PUBLIC → ABSENT
+│       │   │   │
+│       │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 3}
+│       │   │         rule: "column dependents removed after column no longer public"
+│       │   │
+│       │   ├── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+│       │   │     PUBLIC → VALIDATED
+│       │   │
+│       │   └── • IndexName:{DescID: 104, Name: t_expr_idx, IndexID: 2}
+│       │       │ PUBLIC → ABSENT
+│       │       │
+│       │       └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+│       │             rule: "index no longer public before dependents removed"
+│       │
+│       ├── • 3 elements transitioning toward PUBLIC
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │   │         rule: "index-column added to index after index exists"
+│       │   │
+│       │   ├── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │   │     ABSENT → BACKFILL_ONLY
+│       │   │
+│       │   └── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+│       │       │ ABSENT → PUBLIC
+│       │       │
+│       │       └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│       │             rule: "temp index exists before columns, partitioning, and partial"
+│       │             rule: "index-column added to index after temp index exists"
+│       │
+│       ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│       │   │
+│       │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│       │         ABSENT → DELETE_ONLY
+│       │
+│       └── • 12 Mutation operations
+│           │
+│           ├── • MakeDroppedColumnDeleteAndWriteOnly
+│           │     ColumnID: 2
+│           │     TableID: 104
+│           │
+│           ├── • LogEvent
+│           │     Element:
+│           │       Column:
+│           │         columnId: 2
+│           │         pgAttributeNum: 2
+│           │         tableId: 104
+│           │     EventBase:
+│           │       Authorization:
+│           │         UserName: root
+│           │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│           │       StatementTag: ALTER TABLE
+│           │       TargetMetadata:
+│           │         SourceElementID: 1
+│           │         SubWorkID: 1
+│           │     TargetStatus: 1
+│           │
+│           ├── • SetColumnName
+│           │     ColumnID: 2
+│           │     Name: crdb_internal_column_2_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeDroppedColumnDeleteAndWriteOnly
+│           │     ColumnID: 3
+│           │     TableID: 104
+│           │
+│           ├── • LogEvent
+│           │     Element:
+│           │       Column:
+│           │         columnId: 3
+│           │         isInaccessible: true
+│           │         pgAttributeNum: 3
+│           │         tableId: 104
+│           │     EventBase:
+│           │       Authorization:
+│           │         UserName: root
+│           │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│           │       StatementTag: ALTER TABLE
+│           │       TargetMetadata:
+│           │         SourceElementID: 1
+│           │         SubWorkID: 1
+│           │     TargetStatus: 1
+│           │
+│           ├── • SetColumnName
+│           │     ColumnID: 3
+│           │     Name: crdb_internal_column_3_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeDroppedNonPrimaryIndexDeleteAndWriteOnly
+│           │     IndexID: 2
+│           │     TableID: 104
+│           │
+│           ├── • SetIndexName
+│           │     IndexID: 2
+│           │     Name: crdb_internal_index_2_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeAddedIndexBackfilling
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 3
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 104
+│           │       TemporaryIndexID: 4
+│           │
+│           ├── • MakeAddedTempIndexDeleteOnly
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 4
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 104
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 1
+│           │     IndexID: 4
+│           │     TableID: 104
+│           │
+│           └── • AddColumnToIndex
+│                 ColumnID: 1
+│                 IndexID: 3
+│                 TableID: 104
+│
+├── • PreCommitPhase
+│   │
+│   └── • Stage 1 of 1 in PreCommitPhase
+│       │
+│       └── • 2 Mutation operations
+│           │
+│           ├── • SetJobStateOnDescriptor
+│           │     DescriptorID: 104
+│           │     Initialize: true
+│           │
+│           └── • CreateSchemaChangerJob
+│                 Authorization:
+│                   UserName: root
+│                 DescriptorIDs:
+│                 - 104
+│                 JobID: 1
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
+│                 Statements:
+│                 - statement: ALTER TABLE t DROP COLUMN j CASCADE
+│                   redactedstatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│                   statementtag: ALTER TABLE
+│
+├── • PostCommitPhase
+│   │
+│   ├── • Stage 1 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│   │   │   │
+│   │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │       │ DELETE_ONLY → WRITE_ONLY
+│   │   │       │
+│   │   │       └── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+│   │   │             rule: "index-column added to index before temp index receives writes"
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       │     IndexID: 4
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 2 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │       │ BACKFILL_ONLY → BACKFILLED
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       └── • Precedence dependency from WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │             rule: "temp index is WRITE_ONLY before backfill"
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • BackfillIndex
+│   │             IndexID: 3
+│   │             SourceIndexID: 1
+│   │             TableID: 104
+│   │
+│   ├── • Stage 3 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         BACKFILLED → DELETE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfillingIndexDeleteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
+│   │
+│   ├── • Stage 4 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         DELETE_ONLY → MERGE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfilledIndexMerging
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 5 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGE_ONLY → MERGED
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • MergeIndex
+│   │             BackfilledIndexID: 3
+│   │             TableID: 104
+│   │             TemporaryIndexID: 4
+│   │
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
+│       │
+│       ├── • 1 element transitioning toward PUBLIC
+│       │   │
+│       │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │         WRITE_ONLY → VALIDATED
+│       │
+│       └── • 1 Validation operation
+│           │
+│           └── • ValidateUniqueIndex
+│                 IndexID: 3
+│                 TableID: 104
+│
+└── • PostCommitNonRevertiblePhase
+    │
+    ├── • Stage 1 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 9 elements transitioning toward ABSENT
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 2}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 3}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │     PUBLIC → WRITE_ONLY
+    │   │   │
+    │   │   ├── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │         VALIDATED → DELETE_ONLY
+    │   │
+    │   ├── • 2 elements transitioning toward PUBLIC
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+    │   │   │   │ VALIDATED → PUBLIC
+    │   │   │   │
+    │   │   │   ├── • SameStagePrecedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │   │     rule: "primary index swap"
+    │   │   │   │
+    │   │   │   └── • SameStagePrecedence dependency from PUBLIC IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+    │   │   │         rule: "index named right before index becomes public"
+    │   │   │
+    │   │   └── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+    │   │       │ ABSENT → PUBLIC
+    │   │       │
+    │   │       └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+    │   │             rule: "index existence precedes index name and comment"
+    │   │
+    │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+    │   │   │
+    │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+    │   │         WRITE_ONLY → TRANSIENT_DELETE_ONLY
+    │   │
+    │   └── • 14 Mutation operations
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 3
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedPrimaryIndexDeleteAndWriteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 1
+    │       │     Name: crdb_internal_index_1_name_placeholder
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 3
+    │       │     Name: t_pkey
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 4
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 2
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeAddedPrimaryIndexPublic
+    │       │     EventBase:
+    │       │       Authorization:
+    │       │         UserName: root
+    │       │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+    │       │       StatementTag: ALTER TABLE
+    │       │       TargetMetadata:
+    │       │         SourceElementID: 1
+    │       │         SubWorkID: 1
+    │       │     IndexID: 3
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 2
+    │       │     Kind: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending
+    │
+    ├── • Stage 2 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 1 element transitioning toward ABSENT
+    │   │   │
+    │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │         WRITE_ONLY → DELETE_ONLY
+    │   │
+    │   └── • 3 Mutation operations
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 3 of 3 with 9 MutationType ops pending
+    │
+    └── • Stage 3 of 3 in PostCommitNonRevertiblePhase
+        │
+        ├── • 6 elements transitioning toward ABSENT
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 2}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │         rule: "indexes containing columns reach absent before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 3}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 3}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │   │         rule: "indexes containing columns reach absent before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 3}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │   │         rule: "temp indexes reach absent at the same time as other indexes"
+        │   │
+        │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │       │ DELETE_ONLY → ABSENT
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_expr_idx, IndexID: 2}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │             rule: "temp indexes reach absent at the same time as other indexes"
+        │
+        ├── • 1 element transitioning toward TRANSIENT_ABSENT
+        │   │
+        │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │         TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT
+        │
+        └── • 11 Mutation operations
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 1
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     IndexID: 1
+            │     TableID: 104
+            │
+            ├── • LogEvent
+            │     Element:
+            │       SecondaryIndex:
+            │         indexId: 2
+            │         tableId: 104
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TargetStatus: 1
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 2
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 2
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 2
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 3
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • RemoveJobStateFromDescriptor
+            │     DescriptorID: 104
+            │     JobID: 1
+            │
+            └── • UpdateSchemaChangerJob
+                  IsNonCancelable: true
+                  JobID: 1
+                  RunningStatus: all stages completed
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_create_index_separate_statements.0 b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_create_index_separate_statements.0
new file mode 100644
index 000000000000..e5680981ea52
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_create_index_separate_statements.0
@@ -0,0 +1,708 @@
+/* setup */
+create table t (i int primary key, j int, k int default 32 on update 42, index((j+1), k));
+
+/* test */
+EXPLAIN (ddl, verbose) alter table t drop column j cascade;
+----
+• Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE; 
+│
+├── • StatementPhase
+│   │
+│   └── • Stage 1 of 1 in StatementPhase
+│       │
+│       ├── • 6 elements transitioning toward ABSENT
+│       │   │
+│       │   ├── • Column:{DescID: 104, ColumnID: 2}
+│       │   │     PUBLIC → WRITE_ONLY
+│       │   │
+│       │   ├── • ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+│       │   │   │ PUBLIC → ABSENT
+│       │   │   │
+│       │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+│       │   │         rule: "column dependents removed after column no longer public"
+│       │   │
+│       │   ├── • Column:{DescID: 104, ColumnID: 4}
+│       │   │     PUBLIC → WRITE_ONLY
+│       │   │
+│       │   ├── • ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 4}
+│       │   │   │ PUBLIC → ABSENT
+│       │   │   │
+│       │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 4}
+│       │   │         rule: "column dependents removed after column no longer public"
+│       │   │
+│       │   ├── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+│       │   │     PUBLIC → VALIDATED
+│       │   │
+│       │   └── • IndexName:{DescID: 104, Name: t_expr_k_idx, IndexID: 2}
+│       │       │ PUBLIC → ABSENT
+│       │       │
+│       │       └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+│       │             rule: "index no longer public before dependents removed"
+│       │
+│       ├── • 5 elements transitioning toward PUBLIC
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │   │         rule: "index-column added to index after index exists"
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │   │         rule: "index-column added to index after index exists"
+│       │   │
+│       │   ├── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │   │     ABSENT → BACKFILL_ONLY
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│       │   │         rule: "temp index exists before columns, partitioning, and partial"
+│       │   │         rule: "index-column added to index after temp index exists"
+│       │   │
+│       │   └── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}
+│       │       │ ABSENT → PUBLIC
+│       │       │
+│       │       └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│       │             rule: "temp index exists before columns, partitioning, and partial"
+│       │             rule: "index-column added to index after temp index exists"
+│       │
+│       ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│       │   │
+│       │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│       │         ABSENT → DELETE_ONLY
+│       │
+│       └── • 14 Mutation operations
+│           │
+│           ├── • MakeDroppedColumnDeleteAndWriteOnly
+│           │     ColumnID: 2
+│           │     TableID: 104
+│           │
+│           ├── • LogEvent
+│           │     Element:
+│           │       Column:
+│           │         columnId: 2
+│           │         pgAttributeNum: 2
+│           │         tableId: 104
+│           │     EventBase:
+│           │       Authorization:
+│           │         UserName: root
+│           │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│           │       StatementTag: ALTER TABLE
+│           │       TargetMetadata:
+│           │         SourceElementID: 1
+│           │         SubWorkID: 1
+│           │     TargetStatus: 1
+│           │
+│           ├── • SetColumnName
+│           │     ColumnID: 2
+│           │     Name: crdb_internal_column_2_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeDroppedColumnDeleteAndWriteOnly
+│           │     ColumnID: 4
+│           │     TableID: 104
+│           │
+│           ├── • LogEvent
+│           │     Element:
+│           │       Column:
+│           │         columnId: 4
+│           │         isInaccessible: true
+│           │         pgAttributeNum: 4
+│           │         tableId: 104
+│           │     EventBase:
+│           │       Authorization:
+│           │         UserName: root
+│           │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│           │       StatementTag: ALTER TABLE
+│           │       TargetMetadata:
+│           │         SourceElementID: 1
+│           │         SubWorkID: 1
+│           │     TargetStatus: 1
+│           │
+│           ├── • SetColumnName
+│           │     ColumnID: 4
+│           │     Name: crdb_internal_column_4_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeDroppedNonPrimaryIndexDeleteAndWriteOnly
+│           │     IndexID: 2
+│           │     TableID: 104
+│           │
+│           ├── • SetIndexName
+│           │     IndexID: 2
+│           │     Name: crdb_internal_index_2_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeAddedIndexBackfilling
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 3
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 104
+│           │       TemporaryIndexID: 4
+│           │
+│           ├── • MakeAddedTempIndexDeleteOnly
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 4
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 104
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 1
+│           │     IndexID: 4
+│           │     TableID: 104
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 3
+│           │     IndexID: 4
+│           │     Kind: 2
+│           │     TableID: 104
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 1
+│           │     IndexID: 3
+│           │     TableID: 104
+│           │
+│           └── • AddColumnToIndex
+│                 ColumnID: 3
+│                 IndexID: 3
+│                 Kind: 2
+│                 TableID: 104
+│
+├── • PreCommitPhase
+│   │
+│   └── • Stage 1 of 1 in PreCommitPhase
+│       │
+│       └── • 2 Mutation operations
+│           │
+│           ├── • SetJobStateOnDescriptor
+│           │     DescriptorID: 104
+│           │     Initialize: true
+│           │
+│           └── • CreateSchemaChangerJob
+│                 Authorization:
+│                   UserName: root
+│                 DescriptorIDs:
+│                 - 104
+│                 JobID: 1
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
+│                 Statements:
+│                 - statement: ALTER TABLE t DROP COLUMN j CASCADE
+│                   redactedstatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│                   statementtag: ALTER TABLE
+│
+├── • PostCommitPhase
+│   │
+│   ├── • Stage 1 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│   │   │   │
+│   │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │       │ DELETE_ONLY → WRITE_ONLY
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+│   │   │       │     rule: "index-column added to index before temp index receives writes"
+│   │   │       │
+│   │   │       └── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}
+│   │   │             rule: "index-column added to index before temp index receives writes"
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       │     IndexID: 4
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 2 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │       │ BACKFILL_ONLY → BACKFILLED
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       └── • Precedence dependency from WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │             rule: "temp index is WRITE_ONLY before backfill"
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • BackfillIndex
+│   │             IndexID: 3
+│   │             SourceIndexID: 1
+│   │             TableID: 104
+│   │
+│   ├── • Stage 3 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         BACKFILLED → DELETE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfillingIndexDeleteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
+│   │
+│   ├── • Stage 4 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         DELETE_ONLY → MERGE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfilledIndexMerging
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 5 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGE_ONLY → MERGED
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • MergeIndex
+│   │             BackfilledIndexID: 3
+│   │             TableID: 104
+│   │             TemporaryIndexID: 4
+│   │
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
+│       │
+│       ├── • 1 element transitioning toward PUBLIC
+│       │   │
+│       │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │         WRITE_ONLY → VALIDATED
+│       │
+│       └── • 1 Validation operation
+│           │
+│           └── • ValidateUniqueIndex
+│                 IndexID: 3
+│                 TableID: 104
+│
+└── • PostCommitNonRevertiblePhase
+    │
+    ├── • Stage 1 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 11 elements transitioning toward ABSENT
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 2}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 4}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │     PUBLIC → WRITE_ONLY
+    │   │   │
+    │   │   ├── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │         VALIDATED → DELETE_ONLY
+    │   │
+    │   ├── • 2 elements transitioning toward PUBLIC
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+    │   │   │   │ VALIDATED → PUBLIC
+    │   │   │   │
+    │   │   │   ├── • SameStagePrecedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │   │     rule: "primary index swap"
+    │   │   │   │
+    │   │   │   └── • SameStagePrecedence dependency from PUBLIC IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+    │   │   │         rule: "index named right before index becomes public"
+    │   │   │
+    │   │   └── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+    │   │       │ ABSENT → PUBLIC
+    │   │       │
+    │   │       └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+    │   │             rule: "index existence precedes index name and comment"
+    │   │
+    │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+    │   │   │
+    │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+    │   │         WRITE_ONLY → TRANSIENT_DELETE_ONLY
+    │   │
+    │   └── • 16 Mutation operations
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 4
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedPrimaryIndexDeleteAndWriteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 1
+    │       │     Name: crdb_internal_index_1_name_placeholder
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 3
+    │       │     Name: t_pkey
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 4
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 2
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     Ordinal: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeAddedPrimaryIndexPublic
+    │       │     EventBase:
+    │       │       Authorization:
+    │       │         UserName: root
+    │       │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+    │       │       StatementTag: ALTER TABLE
+    │       │       TargetMetadata:
+    │       │         SourceElementID: 1
+    │       │         SubWorkID: 1
+    │       │     IndexID: 3
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 4
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 2
+    │       │     Ordinal: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 2
+    │       │     Kind: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending
+    │
+    ├── • Stage 2 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 1 element transitioning toward ABSENT
+    │   │   │
+    │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │         WRITE_ONLY → DELETE_ONLY
+    │   │
+    │   └── • 3 Mutation operations
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 3 of 3 with 9 MutationType ops pending
+    │
+    └── • Stage 3 of 3 in PostCommitNonRevertiblePhase
+        │
+        ├── • 6 elements transitioning toward ABSENT
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 2}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │         rule: "indexes containing columns reach absent before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 4}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 4}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │   │         rule: "indexes containing columns reach absent before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 4}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │   │         rule: "temp indexes reach absent at the same time as other indexes"
+        │   │
+        │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │       │ DELETE_ONLY → ABSENT
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_expr_k_idx, IndexID: 2}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │             rule: "temp indexes reach absent at the same time as other indexes"
+        │
+        ├── • 1 element transitioning toward TRANSIENT_ABSENT
+        │   │
+        │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │         TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT
+        │
+        └── • 11 Mutation operations
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 1
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     IndexID: 1
+            │     TableID: 104
+            │
+            ├── • LogEvent
+            │     Element:
+            │       SecondaryIndex:
+            │         indexId: 2
+            │         tableId: 104
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TargetStatus: 1
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 2
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 2
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 2
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 4
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • RemoveJobStateFromDescriptor
+            │     DescriptorID: 104
+            │     JobID: 1
+            │
+            └── • UpdateSchemaChangerJob
+                  IsNonCancelable: true
+                  JobID: 1
+                  RunningStatus: all stages completed
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_create_index_separate_statements.1 b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_create_index_separate_statements.1
new file mode 100644
index 000000000000..8e4a8d43d558
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_create_index_separate_statements.1
@@ -0,0 +1,804 @@
+/* setup */
+create table t (i int primary key, j int, k int default 32 on update 42, index((j+1), k));
+
+/* test */
+alter table t drop column j cascade;
+EXPLAIN (ddl, verbose) create unique index idx on t(k);
+----
+• Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE; CREATE UNIQUE INDEX ‹idx› ON ‹defaultdb›.‹public›.‹t› (‹k›); 
+│
+├── • PreCommitPhase
+│   │
+│   └── • Stage 1 of 1 in PreCommitPhase
+│       │
+│       └── • 2 Mutation operations
+│           │
+│           ├── • SetJobStateOnDescriptor
+│           │     DescriptorID: 104
+│           │     Initialize: true
+│           │
+│           └── • CreateSchemaChangerJob
+│                 Authorization:
+│                   UserName: root
+│                 DescriptorIDs:
+│                 - 104
+│                 JobID: 1
+│                 RunningStatus: PostCommitPhase stage 1 of 15 with 1 MutationType op pending
+│                 Statements:
+│                 - statement: ALTER TABLE t DROP COLUMN j CASCADE
+│                   redactedstatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│                   statementtag: ALTER TABLE
+│                 - statement: CREATE UNIQUE INDEX idx ON t (k)
+│                   redactedstatement: CREATE UNIQUE INDEX ‹idx› ON ‹defaultdb›.‹public›.‹t› (‹k›)
+│                   statementtag: CREATE INDEX
+│
+├── • PostCommitPhase
+│   │
+│   ├── • Stage 1 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│   │   │   │
+│   │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │       │ DELETE_ONLY → WRITE_ONLY
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+│   │   │       │     rule: "index-column added to index before temp index receives writes"
+│   │   │       │
+│   │   │       └── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}
+│   │   │             rule: "index-column added to index before temp index receives writes"
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       │     IndexID: 4
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 2 of 15 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 2 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │       │ BACKFILL_ONLY → BACKFILLED
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       └── • Precedence dependency from WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │             rule: "temp index is WRITE_ONLY before backfill"
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • BackfillIndex
+│   │             IndexID: 3
+│   │             SourceIndexID: 1
+│   │             TableID: 104
+│   │
+│   ├── • Stage 3 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         BACKFILLED → DELETE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfillingIndexDeleteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 4 of 15 with 1 MutationType op pending
+│   │
+│   ├── • Stage 4 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         DELETE_ONLY → MERGE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfilledIndexMerging
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 5 of 15 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 5 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGE_ONLY → MERGED
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • MergeIndex
+│   │             BackfilledIndexID: 3
+│   │             TableID: 104
+│   │             TemporaryIndexID: 4
+│   │
+│   ├── • Stage 6 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 15 with 1 ValidationType op pending
+│   │
+│   ├── • Stage 7 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         WRITE_ONLY → VALIDATED
+│   │   │
+│   │   └── • 1 Validation operation
+│   │       │
+│   │       └── • ValidateUniqueIndex
+│   │             IndexID: 3
+│   │             TableID: 104
+│   │
+│   ├── • Stage 8 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 2 elements transitioning toward ABSENT
+│   │   │   │
+│   │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+│   │   │   │     PUBLIC → VALIDATED
+│   │   │   │
+│   │   │   └── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+│   │   │       │ PUBLIC → ABSENT
+│   │   │       │
+│   │   │       └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+│   │   │             rule: "index no longer public before dependents removed"
+│   │   │
+│   │   ├── • 7 elements transitioning toward PUBLIC
+│   │   │   │
+│   │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │   │   │ VALIDATED → PUBLIC
+│   │   │   │   │
+│   │   │   │   ├── • SameStagePrecedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+│   │   │   │   │     rule: "primary index swap"
+│   │   │   │   │
+│   │   │   │   └── • SameStagePrecedence dependency from PUBLIC IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+│   │   │   │         rule: "index named right before index becomes public"
+│   │   │   │
+│   │   │   ├── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+│   │   │   │   │ ABSENT → PUBLIC
+│   │   │   │   │
+│   │   │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │   │         rule: "index existence precedes index name and comment"
+│   │   │   │
+│   │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 5}
+│   │   │   │   │ ABSENT → PUBLIC
+│   │   │   │   │
+│   │   │   │   └── • Precedence dependency from BACKFILL_ONLY SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+│   │   │   │         rule: "index-column added to index after index exists"
+│   │   │   │
+│   │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 5}
+│   │   │   │   │ ABSENT → PUBLIC
+│   │   │   │   │
+│   │   │   │   └── • Precedence dependency from BACKFILL_ONLY SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+│   │   │   │         rule: "index-column added to index after index exists"
+│   │   │   │
+│   │   │   ├── • SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+│   │   │   │   │ ABSENT → BACKFILL_ONLY
+│   │   │   │   │
+│   │   │   │   └── • Precedence dependency from PUBLIC PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │   │         rule: "primary index with new columns should exist before secondary indexes"
+│   │   │   │
+│   │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 6}
+│   │   │   │   │ ABSENT → PUBLIC
+│   │   │   │   │
+│   │   │   │   └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+│   │   │   │         rule: "temp index exists before columns, partitioning, and partial"
+│   │   │   │         rule: "index-column added to index after temp index exists"
+│   │   │   │
+│   │   │   └── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 6}
+│   │   │       │ ABSENT → PUBLIC
+│   │   │       │
+│   │   │       └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+│   │   │             rule: "temp index exists before columns, partitioning, and partial"
+│   │   │             rule: "index-column added to index after temp index exists"
+│   │   │
+│   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│   │   │   │
+│   │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+│   │   │       │ ABSENT → DELETE_ONLY
+│   │   │       │
+│   │   │       └── • Precedence dependency from PUBLIC PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │             rule: "primary index with new columns should exist before temp indexes"
+│   │   │
+│   │   └── • 12 Mutation operations
+│   │       │
+│   │       ├── • MakeDroppedPrimaryIndexDeleteAndWriteOnly
+│   │       │     IndexID: 1
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetIndexName
+│   │       │     IndexID: 1
+│   │       │     Name: crdb_internal_index_1_name_placeholder
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetIndexName
+│   │       │     IndexID: 3
+│   │       │     Name: t_pkey
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • MakeAddedPrimaryIndexPublic
+│   │       │     EventBase:
+│   │       │       Authorization:
+│   │       │         UserName: root
+│   │       │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│   │       │       StatementTag: ALTER TABLE
+│   │       │       TargetMetadata:
+│   │       │         SourceElementID: 1
+│   │       │         SubWorkID: 1
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • MakeAddedIndexBackfilling
+│   │       │     Index:
+│   │       │       IndexID: 5
+│   │       │       IsUnique: true
+│   │       │       SourceIndexID: 3
+│   │       │       TableID: 104
+│   │       │       TemporaryIndexID: 6
+│   │       │     IsSecondaryIndex: true
+│   │       │
+│   │       ├── • MakeAddedTempIndexDeleteOnly
+│   │       │     Index:
+│   │       │       IndexID: 6
+│   │       │       IsUnique: true
+│   │       │       SourceIndexID: 3
+│   │       │       TableID: 104
+│   │       │     IsSecondaryIndex: true
+│   │       │
+│   │       ├── • AddColumnToIndex
+│   │       │     ColumnID: 3
+│   │       │     IndexID: 6
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • AddColumnToIndex
+│   │       │     ColumnID: 1
+│   │       │     IndexID: 6
+│   │       │     Kind: 1
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • AddColumnToIndex
+│   │       │     ColumnID: 3
+│   │       │     IndexID: 5
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • AddColumnToIndex
+│   │       │     ColumnID: 1
+│   │       │     IndexID: 5
+│   │       │     Kind: 1
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 9 of 15 with 1 MutationType op pending
+│   │
+│   ├── • Stage 9 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│   │   │   │
+│   │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+│   │   │       │ DELETE_ONLY → WRITE_ONLY
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 6}
+│   │   │       │     rule: "index-column added to index before temp index receives writes"
+│   │   │       │
+│   │   │       └── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 6}
+│   │   │             rule: "index-column added to index before temp index receives writes"
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       │     IndexID: 6
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 10 of 15 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 10 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+│   │   │       │ BACKFILL_ONLY → BACKFILLED
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 5}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 5}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       └── • Precedence dependency from WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+│   │   │             rule: "temp index is WRITE_ONLY before backfill"
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • BackfillIndex
+│   │             IndexID: 5
+│   │             SourceIndexID: 3
+│   │             TableID: 104
+│   │
+│   ├── • Stage 11 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+│   │   │         BACKFILLED → DELETE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfillingIndexDeleteOnly
+│   │       │     IndexID: 5
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 12 of 15 with 1 MutationType op pending
+│   │
+│   ├── • Stage 12 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+│   │   │         DELETE_ONLY → MERGE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfilledIndexMerging
+│   │       │     IndexID: 5
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 13 of 15 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 13 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+│   │   │         MERGE_ONLY → MERGED
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • MergeIndex
+│   │             BackfilledIndexID: 5
+│   │             TableID: 104
+│   │             TemporaryIndexID: 6
+│   │
+│   ├── • Stage 14 of 15 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 5
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 15 of 15 with 1 ValidationType op pending
+│   │
+│   └── • Stage 15 of 15 in PostCommitPhase
+│       │
+│       ├── • 1 element transitioning toward PUBLIC
+│       │   │
+│       │   └── • SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+│       │         WRITE_ONLY → VALIDATED
+│       │
+│       └── • 1 Validation operation
+│           │
+│           └── • ValidateUniqueIndex
+│                 IndexID: 5
+│                 TableID: 104
+│
+└── • PostCommitNonRevertiblePhase
+    │
+    ├── • Stage 1 of 2 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 10 elements transitioning toward ABSENT
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 2}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 4}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │     VALIDATED → DELETE_ONLY
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │         VALIDATED → DELETE_ONLY
+    │   │
+    │   ├── • 2 elements transitioning toward PUBLIC
+    │   │   │
+    │   │   ├── • SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+    │   │   │   │ VALIDATED → PUBLIC
+    │   │   │   │
+    │   │   │   └── • SameStagePrecedence dependency from PUBLIC IndexName:{DescID: 104, Name: idx, IndexID: 5}
+    │   │   │         rule: "index named right before index becomes public"
+    │   │   │
+    │   │   └── • IndexName:{DescID: 104, Name: idx, IndexID: 5}
+    │   │       │ ABSENT → PUBLIC
+    │   │       │
+    │   │       └── • Precedence dependency from BACKFILL_ONLY SecondaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 0, TemporaryIndexID: 6, SourceIndexID: 3}
+    │   │             rule: "index existence precedes index name and comment"
+    │   │
+    │   ├── • 2 elements transitioning toward TRANSIENT_ABSENT
+    │   │   │
+    │   │   ├── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+    │   │   │     WRITE_ONLY → TRANSIENT_DELETE_ONLY
+    │   │   │
+    │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+    │   │         WRITE_ONLY → TRANSIENT_DELETE_ONLY
+    │   │
+    │   └── • 16 Mutation operations
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 4
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 2
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     Ordinal: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 4
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 5
+    │       │     Name: idx
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 6
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeAddedSecondaryIndexPublic
+    │       │     IndexID: 5
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 4
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 2
+    │       │     Ordinal: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 2
+    │       │     Kind: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 2 of 2 with 11 MutationType ops
+    │               pending
+    │
+    └── • Stage 2 of 2 in PostCommitNonRevertiblePhase
+        │
+        ├── • 6 elements transitioning toward ABSENT
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 2}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │   │     rule: "indexes containing columns reach absent before column"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+        │   │         rule: "dependents removed before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 4}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │   │   │     rule: "indexes containing columns reach absent before column"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 4}
+        │   │         rule: "dependents removed before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 4}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │   │   │     rule: "temp indexes reach absent at the same time as other indexes"
+        │   │   │
+        │   │   └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+        │   │         rule: "temp indexes reach absent at the same time as other indexes"
+        │   │
+        │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │       │ DELETE_ONLY → ABSENT
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_expr_k_idx, IndexID: 2}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │       │     rule: "temp indexes reach absent at the same time as other indexes"
+        │       │
+        │       └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+        │             rule: "temp indexes reach absent at the same time as other indexes"
+        │
+        ├── • 2 elements transitioning toward TRANSIENT_ABSENT
+        │   │
+        │   ├── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │   │     TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT
+        │   │
+        │   └── • TemporaryIndex:{DescID: 104, IndexID: 6, SourceIndexID: 3}
+        │         TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT
+        │
+        └── • 13 Mutation operations
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 6
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 6
+            │     TableID: 104
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 1
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     IndexID: 1
+            │     TableID: 104
+            │
+            ├── • LogEvent
+            │     Element:
+            │       SecondaryIndex:
+            │         indexId: 2
+            │         tableId: 104
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TargetStatus: 1
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 2
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 2
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 2
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 4
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • RemoveJobStateFromDescriptor
+            │     DescriptorID: 104
+            │     JobID: 1
+            │
+            └── • UpdateSchemaChangerJob
+                  IsNonCancelable: true
+                  JobID: 1
+                  RunningStatus: all stages completed
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_unique_index b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_unique_index
new file mode 100644
index 000000000000..22c510e63749
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_unique_index
@@ -0,0 +1,582 @@
+/* setup */
+CREATE DATABASE t;
+CREATE TABLE t.test (k INT PRIMARY KEY, v INT, pi DECIMAL DEFAULT (DECIMAL '3.14'));
+CREATE UNIQUE INDEX vidx ON t.test (v);
+ALTER TABLE t.test ADD COLUMN x DECIMAL DEFAULT (DECIMAL '1.4') CHECK (x >= 0);
+
+/* test */
+EXPLAIN (ddl, verbose) ALTER TABLE t.test DROP pi;
+----
+• Schema change plan for ALTER TABLE ‹t›.‹public›.‹test› DROP COLUMN ‹pi›; 
+│
+├── • StatementPhase
+│   │
+│   └── • Stage 1 of 1 in StatementPhase
+│       │
+│       ├── • 2 elements transitioning toward ABSENT
+│       │   │
+│       │   ├── • Column:{DescID: 106, ColumnID: 3}
+│       │   │     PUBLIC → WRITE_ONLY
+│       │   │
+│       │   └── • ColumnName:{DescID: 106, Name: pi, ColumnID: 3}
+│       │       │ PUBLIC → ABSENT
+│       │       │
+│       │       └── • Precedence dependency from WRITE_ONLY Column:{DescID: 106, ColumnID: 3}
+│       │             rule: "column dependents removed after column no longer public"
+│       │
+│       ├── • 7 elements transitioning toward PUBLIC
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 4}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+│       │   │         rule: "index-column added to index after index exists"
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 4}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+│       │   │         rule: "index-column added to index after index exists"
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 106, ColumnID: 4, IndexID: 4}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+│       │   │         rule: "index-column added to index after index exists"
+│       │   │
+│       │   ├── • PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+│       │   │     ABSENT → BACKFILL_ONLY
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 5}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+│       │   │         rule: "temp index exists before columns, partitioning, and partial"
+│       │   │         rule: "index-column added to index after temp index exists"
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 5}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+│       │   │         rule: "temp index exists before columns, partitioning, and partial"
+│       │   │         rule: "index-column added to index after temp index exists"
+│       │   │
+│       │   └── • IndexColumn:{DescID: 106, ColumnID: 4, IndexID: 5}
+│       │       │ ABSENT → PUBLIC
+│       │       │
+│       │       └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+│       │             rule: "temp index exists before columns, partitioning, and partial"
+│       │             rule: "index-column added to index after temp index exists"
+│       │
+│       ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│       │   │
+│       │   └── • TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+│       │         ABSENT → DELETE_ONLY
+│       │
+│       └── • 11 Mutation operations
+│           │
+│           ├── • MakeDroppedColumnDeleteAndWriteOnly
+│           │     ColumnID: 3
+│           │     TableID: 106
+│           │
+│           ├── • LogEvent
+│           │     Element:
+│           │       Column:
+│           │         columnId: 3
+│           │         pgAttributeNum: 3
+│           │         tableId: 106
+│           │     EventBase:
+│           │       Authorization:
+│           │         UserName: root
+│           │       Statement: ALTER TABLE ‹t›.‹public›.‹test› DROP COLUMN ‹pi›
+│           │       StatementTag: ALTER TABLE
+│           │       TargetMetadata:
+│           │         SourceElementID: 1
+│           │         SubWorkID: 1
+│           │     TargetStatus: 1
+│           │
+│           ├── • SetColumnName
+│           │     ColumnID: 3
+│           │     Name: crdb_internal_column_3_name_placeholder
+│           │     TableID: 106
+│           │
+│           ├── • MakeAddedIndexBackfilling
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 4
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 106
+│           │       TemporaryIndexID: 5
+│           │
+│           ├── • MakeAddedTempIndexDeleteOnly
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 5
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 106
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 1
+│           │     IndexID: 5
+│           │     TableID: 106
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 2
+│           │     IndexID: 5
+│           │     Kind: 2
+│           │     TableID: 106
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 4
+│           │     IndexID: 5
+│           │     Kind: 2
+│           │     Ordinal: 1
+│           │     TableID: 106
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 1
+│           │     IndexID: 4
+│           │     TableID: 106
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 2
+│           │     IndexID: 4
+│           │     Kind: 2
+│           │     TableID: 106
+│           │
+│           └── • AddColumnToIndex
+│                 ColumnID: 4
+│                 IndexID: 4
+│                 Kind: 2
+│                 Ordinal: 1
+│                 TableID: 106
+│
+├── • PreCommitPhase
+│   │
+│   └── • Stage 1 of 1 in PreCommitPhase
+│       │
+│       └── • 2 Mutation operations
+│           │
+│           ├── • SetJobStateOnDescriptor
+│           │     DescriptorID: 106
+│           │     Initialize: true
+│           │
+│           └── • CreateSchemaChangerJob
+│                 Authorization:
+│                   UserName: root
+│                 DescriptorIDs:
+│                 - 106
+│                 JobID: 1
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
+│                 Statements:
+│                 - statement: ALTER TABLE t.test DROP COLUMN pi
+│                   redactedstatement: ALTER TABLE ‹t›.‹public›.‹test› DROP COLUMN ‹pi›
+│                   statementtag: ALTER TABLE
+│
+├── • PostCommitPhase
+│   │
+│   ├── • Stage 1 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│   │   │   │
+│   │   │   └── • TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+│   │   │       │ DELETE_ONLY → WRITE_ONLY
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 5}
+│   │   │       │     rule: "index-column added to index before temp index receives writes"
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 5}
+│   │   │       │     rule: "index-column added to index before temp index receives writes"
+│   │   │       │
+│   │   │       └── • Precedence dependency from PUBLIC IndexColumn:{DescID: 106, ColumnID: 4, IndexID: 5}
+│   │   │             rule: "index-column added to index before temp index receives writes"
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       │     IndexID: 5
+│   │       │     TableID: 106
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 106
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 2 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+│   │   │       │ BACKFILL_ONLY → BACKFILLED
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 4}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 4}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 106, ColumnID: 4, IndexID: 4}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       └── • Precedence dependency from WRITE_ONLY TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+│   │   │             rule: "temp index is WRITE_ONLY before backfill"
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • BackfillIndex
+│   │             IndexID: 4
+│   │             SourceIndexID: 1
+│   │             TableID: 106
+│   │
+│   ├── • Stage 3 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+│   │   │         BACKFILLED → DELETE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfillingIndexDeleteOnly
+│   │       │     IndexID: 4
+│   │       │     TableID: 106
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 106
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
+│   │
+│   ├── • Stage 4 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+│   │   │         DELETE_ONLY → MERGE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfilledIndexMerging
+│   │       │     IndexID: 4
+│   │       │     TableID: 106
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 106
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 5 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+│   │   │         MERGE_ONLY → MERGED
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • MergeIndex
+│   │             BackfilledIndexID: 4
+│   │             TableID: 106
+│   │             TemporaryIndexID: 5
+│   │
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 4
+│   │       │     TableID: 106
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 106
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
+│       │
+│       ├── • 1 element transitioning toward PUBLIC
+│       │   │
+│       │   └── • PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+│       │         WRITE_ONLY → VALIDATED
+│       │
+│       └── • 1 Validation operation
+│           │
+│           └── • ValidateUniqueIndex
+│                 IndexID: 4
+│                 TableID: 106
+│
+└── • PostCommitNonRevertiblePhase
+    │
+    ├── • Stage 1 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 7 elements transitioning toward ABSENT
+    │   │   │
+    │   │   ├── • Column:{DescID: 106, ColumnID: 3}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 106, ColumnID: 3, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 106, ColumnID: 4, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+    │   │   │     PUBLIC → WRITE_ONLY
+    │   │   │
+    │   │   └── • IndexName:{DescID: 106, Name: test_pkey, IndexID: 1}
+    │   │       │ PUBLIC → ABSENT
+    │   │       │
+    │   │       └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+    │   │             rule: "index no longer public before dependents removed"
+    │   │
+    │   ├── • 2 elements transitioning toward PUBLIC
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+    │   │   │   │ VALIDATED → PUBLIC
+    │   │   │   │
+    │   │   │   ├── • SameStagePrecedence dependency from VALIDATED PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+    │   │   │   │     rule: "primary index swap"
+    │   │   │   │
+    │   │   │   └── • SameStagePrecedence dependency from PUBLIC IndexName:{DescID: 106, Name: test_pkey, IndexID: 4}
+    │   │   │         rule: "index named right before index becomes public"
+    │   │   │
+    │   │   └── • IndexName:{DescID: 106, Name: test_pkey, IndexID: 4}
+    │   │       │ ABSENT → PUBLIC
+    │   │       │
+    │   │       └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 106, IndexID: 4, ConstraintID: 1, TemporaryIndexID: 5, SourceIndexID: 1}
+    │   │             rule: "index existence precedes index name and comment"
+    │   │
+    │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+    │   │   │
+    │   │   └── • TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+    │   │         WRITE_ONLY → TRANSIENT_DELETE_ONLY
+    │   │
+    │   └── • 12 Mutation operations
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 3
+    │       │     TableID: 106
+    │       │
+    │       ├── • MakeDroppedPrimaryIndexDeleteAndWriteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 106
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 1
+    │       │     Name: crdb_internal_index_1_name_placeholder
+    │       │     TableID: 106
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 4
+    │       │     Name: test_pkey
+    │       │     TableID: 106
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 5
+    │       │     TableID: 106
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 1
+    │       │     TableID: 106
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 2
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     TableID: 106
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     Ordinal: 1
+    │       │     TableID: 106
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 4
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     Ordinal: 2
+    │       │     TableID: 106
+    │       │
+    │       ├── • MakeAddedPrimaryIndexPublic
+    │       │     EventBase:
+    │       │       Authorization:
+    │       │         UserName: root
+    │       │       Statement: ALTER TABLE ‹t›.‹public›.‹test› DROP COLUMN ‹pi›
+    │       │       StatementTag: ALTER TABLE
+    │       │       TargetMetadata:
+    │       │         SourceElementID: 1
+    │       │         SubWorkID: 1
+    │       │     IndexID: 4
+    │       │     TableID: 106
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 106
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending
+    │
+    ├── • Stage 2 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 1 element transitioning toward ABSENT
+    │   │   │
+    │   │   └── • PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+    │   │         WRITE_ONLY → DELETE_ONLY
+    │   │
+    │   └── • 3 Mutation operations
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 106
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 106
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 3 of 3 with 6 MutationType ops pending
+    │
+    └── • Stage 3 of 3 in PostCommitNonRevertiblePhase
+        │
+        ├── • 4 elements transitioning toward ABSENT
+        │   │
+        │   ├── • Column:{DescID: 106, ColumnID: 3}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 106, Name: pi, ColumnID: 3}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 106, ColumnFamilyID: 0, ColumnID: 3}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+        │   │         rule: "indexes containing columns reach absent before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 106, ColumnFamilyID: 0, ColumnID: 3}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from WRITE_ONLY Column:{DescID: 106, ColumnID: 3}
+        │   │   │     rule: "column dependents removed after column no longer public"
+        │   │   │
+        │   │   └── • SameStagePrecedence dependency from ABSENT ColumnDefaultExpression:{DescID: 106, ColumnID: 3}
+        │   │         rule: "column type dependents removed right before column type"
+        │   │
+        │   ├── • ColumnDefaultExpression:{DescID: 106, ColumnID: 3}
+        │   │     PUBLIC → ABSENT
+        │   │
+        │   └── • PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+        │       │ DELETE_ONLY → ABSENT
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 1}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 1}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 106, ColumnID: 3, IndexID: 1}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 106, ColumnID: 4, IndexID: 1}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexName:{DescID: 106, Name: test_pkey, IndexID: 1}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+        │             rule: "temp indexes reach absent at the same time as other indexes"
+        │
+        ├── • 1 element transitioning toward TRANSIENT_ABSENT
+        │   │
+        │   └── • TemporaryIndex:{DescID: 106, IndexID: 5, SourceIndexID: 1}
+        │         TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT
+        │
+        └── • 8 Mutation operations
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 5
+            │     TableID: 106
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 5
+            │     TableID: 106
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 1
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE t.public.test DROP COLUMN pi
+            │     TableID: 106
+            │
+            ├── • MakeIndexAbsent
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹t›.‹public›.‹test› DROP COLUMN ‹pi›
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     IndexID: 1
+            │     TableID: 106
+            │
+            ├── • RemoveColumnDefaultExpression
+            │     ColumnID: 3
+            │     TableID: 106
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 3
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹t›.‹public›.‹test› DROP COLUMN ‹pi›
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 106
+            │
+            ├── • RemoveJobStateFromDescriptor
+            │     DescriptorID: 106
+            │     JobID: 1
+            │
+            └── • UpdateSchemaChangerJob
+                  IsNonCancelable: true
+                  JobID: 1
+                  RunningStatus: all stages completed
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_with_index b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_with_index
new file mode 100644
index 000000000000..4f82afc2c8ae
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/drop_column_with_index
@@ -0,0 +1,572 @@
+/* setup */
+create table t (i int primary key, j int, index (j));
+
+/* test */
+EXPLAIN (ddl, verbose) alter table t drop column j;
+----
+• Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›; 
+│
+├── • StatementPhase
+│   │
+│   └── • Stage 1 of 1 in StatementPhase
+│       │
+│       ├── • 4 elements transitioning toward ABSENT
+│       │   │
+│       │   ├── • Column:{DescID: 104, ColumnID: 2}
+│       │   │     PUBLIC → WRITE_ONLY
+│       │   │
+│       │   ├── • ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+│       │   │   │ PUBLIC → ABSENT
+│       │   │   │
+│       │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+│       │   │         rule: "column dependents removed after column no longer public"
+│       │   │
+│       │   ├── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+│       │   │     PUBLIC → VALIDATED
+│       │   │
+│       │   └── • IndexName:{DescID: 104, Name: t_j_idx, IndexID: 2}
+│       │       │ PUBLIC → ABSENT
+│       │       │
+│       │       └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+│       │             rule: "index no longer public before dependents removed"
+│       │
+│       ├── • 3 elements transitioning toward PUBLIC
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │   │         rule: "index-column added to index after index exists"
+│       │   │
+│       │   ├── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │   │     ABSENT → BACKFILL_ONLY
+│       │   │
+│       │   └── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+│       │       │ ABSENT → PUBLIC
+│       │       │
+│       │       └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│       │             rule: "temp index exists before columns, partitioning, and partial"
+│       │             rule: "index-column added to index after temp index exists"
+│       │
+│       ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│       │   │
+│       │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│       │         ABSENT → DELETE_ONLY
+│       │
+│       └── • 9 Mutation operations
+│           │
+│           ├── • MakeDroppedColumnDeleteAndWriteOnly
+│           │     ColumnID: 2
+│           │     TableID: 104
+│           │
+│           ├── • LogEvent
+│           │     Element:
+│           │       Column:
+│           │         columnId: 2
+│           │         pgAttributeNum: 2
+│           │         tableId: 104
+│           │     EventBase:
+│           │       Authorization:
+│           │         UserName: root
+│           │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+│           │       StatementTag: ALTER TABLE
+│           │       TargetMetadata:
+│           │         SourceElementID: 1
+│           │         SubWorkID: 1
+│           │     TargetStatus: 1
+│           │
+│           ├── • SetColumnName
+│           │     ColumnID: 2
+│           │     Name: crdb_internal_column_2_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeDroppedNonPrimaryIndexDeleteAndWriteOnly
+│           │     IndexID: 2
+│           │     TableID: 104
+│           │
+│           ├── • SetIndexName
+│           │     IndexID: 2
+│           │     Name: crdb_internal_index_2_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeAddedIndexBackfilling
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 3
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 104
+│           │       TemporaryIndexID: 4
+│           │
+│           ├── • MakeAddedTempIndexDeleteOnly
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 4
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 104
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 1
+│           │     IndexID: 4
+│           │     TableID: 104
+│           │
+│           └── • AddColumnToIndex
+│                 ColumnID: 1
+│                 IndexID: 3
+│                 TableID: 104
+│
+├── • PreCommitPhase
+│   │
+│   └── • Stage 1 of 1 in PreCommitPhase
+│       │
+│       └── • 2 Mutation operations
+│           │
+│           ├── • SetJobStateOnDescriptor
+│           │     DescriptorID: 104
+│           │     Initialize: true
+│           │
+│           └── • CreateSchemaChangerJob
+│                 Authorization:
+│                   UserName: root
+│                 DescriptorIDs:
+│                 - 104
+│                 JobID: 1
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
+│                 Statements:
+│                 - statement: ALTER TABLE t DROP COLUMN j
+│                   redactedstatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+│                   statementtag: ALTER TABLE
+│
+├── • PostCommitPhase
+│   │
+│   ├── • Stage 1 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│   │   │   │
+│   │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │       │ DELETE_ONLY → WRITE_ONLY
+│   │   │       │
+│   │   │       └── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+│   │   │             rule: "index-column added to index before temp index receives writes"
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       │     IndexID: 4
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 2 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │       │ BACKFILL_ONLY → BACKFILLED
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       └── • Precedence dependency from WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │             rule: "temp index is WRITE_ONLY before backfill"
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • BackfillIndex
+│   │             IndexID: 3
+│   │             SourceIndexID: 1
+│   │             TableID: 104
+│   │
+│   ├── • Stage 3 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         BACKFILLED → DELETE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfillingIndexDeleteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
+│   │
+│   ├── • Stage 4 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         DELETE_ONLY → MERGE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfilledIndexMerging
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 5 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGE_ONLY → MERGED
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • MergeIndex
+│   │             BackfilledIndexID: 3
+│   │             TableID: 104
+│   │             TemporaryIndexID: 4
+│   │
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
+│       │
+│       ├── • 1 element transitioning toward PUBLIC
+│       │   │
+│       │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │         WRITE_ONLY → VALIDATED
+│       │
+│       └── • 1 Validation operation
+│           │
+│           └── • ValidateUniqueIndex
+│                 IndexID: 3
+│                 TableID: 104
+│
+└── • PostCommitNonRevertiblePhase
+    │
+    ├── • Stage 1 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 8 elements transitioning toward ABSENT
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 2}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │     PUBLIC → WRITE_ONLY
+    │   │   │
+    │   │   ├── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │         VALIDATED → DELETE_ONLY
+    │   │
+    │   ├── • 2 elements transitioning toward PUBLIC
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+    │   │   │   │ VALIDATED → PUBLIC
+    │   │   │   │
+    │   │   │   ├── • SameStagePrecedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │   │     rule: "primary index swap"
+    │   │   │   │
+    │   │   │   └── • SameStagePrecedence dependency from PUBLIC IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+    │   │   │         rule: "index named right before index becomes public"
+    │   │   │
+    │   │   └── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+    │   │       │ ABSENT → PUBLIC
+    │   │       │
+    │   │       └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+    │   │             rule: "index existence precedes index name and comment"
+    │   │
+    │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+    │   │   │
+    │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+    │   │         WRITE_ONLY → TRANSIENT_DELETE_ONLY
+    │   │
+    │   └── • 13 Mutation operations
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedPrimaryIndexDeleteAndWriteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 1
+    │       │     Name: crdb_internal_index_1_name_placeholder
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 3
+    │       │     Name: t_pkey
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 4
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 2
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeAddedPrimaryIndexPublic
+    │       │     EventBase:
+    │       │       Authorization:
+    │       │         UserName: root
+    │       │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+    │       │       StatementTag: ALTER TABLE
+    │       │       TargetMetadata:
+    │       │         SourceElementID: 1
+    │       │         SubWorkID: 1
+    │       │     IndexID: 3
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 2
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 2
+    │       │     Kind: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending
+    │
+    ├── • Stage 2 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 1 element transitioning toward ABSENT
+    │   │   │
+    │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │         WRITE_ONLY → DELETE_ONLY
+    │   │
+    │   └── • 3 Mutation operations
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 3 of 3 with 8 MutationType ops pending
+    │
+    └── • Stage 3 of 3 in PostCommitNonRevertiblePhase
+        │
+        ├── • 4 elements transitioning toward ABSENT
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 2}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │   │     rule: "indexes containing columns reach absent before column"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │   │         rule: "indexes containing columns reach absent before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │   │         rule: "temp indexes reach absent at the same time as other indexes"
+        │   │
+        │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │       │ DELETE_ONLY → ABSENT
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_j_idx, IndexID: 2}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │             rule: "temp indexes reach absent at the same time as other indexes"
+        │
+        ├── • 1 element transitioning toward TRANSIENT_ABSENT
+        │   │
+        │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │         TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT
+        │
+        └── • 10 Mutation operations
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 1
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     IndexID: 1
+            │     TableID: 104
+            │
+            ├── • LogEvent
+            │     Element:
+            │       SecondaryIndex:
+            │         indexId: 2
+            │         tableId: 104
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TargetStatus: 1
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 2
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 2
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 2
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j›
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • RemoveJobStateFromDescriptor
+            │     DescriptorID: 104
+            │     JobID: 1
+            │
+            └── • UpdateSchemaChangerJob
+                  IsNonCancelable: true
+                  JobID: 1
+                  RunningStatus: all stages completed
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/drop_multiple_columns_separate_statements.0 b/pkg/sql/schemachanger/testdata/explain_verbose/drop_multiple_columns_separate_statements.0
new file mode 100644
index 000000000000..e5680981ea52
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/drop_multiple_columns_separate_statements.0
@@ -0,0 +1,708 @@
+/* setup */
+create table t (i int primary key, j int, k int default 32 on update 42, index((j+1), k));
+
+/* test */
+EXPLAIN (ddl, verbose) alter table t drop column j cascade;
+----
+• Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE; 
+│
+├── • StatementPhase
+│   │
+│   └── • Stage 1 of 1 in StatementPhase
+│       │
+│       ├── • 6 elements transitioning toward ABSENT
+│       │   │
+│       │   ├── • Column:{DescID: 104, ColumnID: 2}
+│       │   │     PUBLIC → WRITE_ONLY
+│       │   │
+│       │   ├── • ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+│       │   │   │ PUBLIC → ABSENT
+│       │   │   │
+│       │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+│       │   │         rule: "column dependents removed after column no longer public"
+│       │   │
+│       │   ├── • Column:{DescID: 104, ColumnID: 4}
+│       │   │     PUBLIC → WRITE_ONLY
+│       │   │
+│       │   ├── • ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 4}
+│       │   │   │ PUBLIC → ABSENT
+│       │   │   │
+│       │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 4}
+│       │   │         rule: "column dependents removed after column no longer public"
+│       │   │
+│       │   ├── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+│       │   │     PUBLIC → VALIDATED
+│       │   │
+│       │   └── • IndexName:{DescID: 104, Name: t_expr_k_idx, IndexID: 2}
+│       │       │ PUBLIC → ABSENT
+│       │       │
+│       │       └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+│       │             rule: "index no longer public before dependents removed"
+│       │
+│       ├── • 5 elements transitioning toward PUBLIC
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │   │         rule: "index-column added to index after index exists"
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │   │         rule: "index-column added to index after index exists"
+│       │   │
+│       │   ├── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │   │     ABSENT → BACKFILL_ONLY
+│       │   │
+│       │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+│       │   │   │ ABSENT → PUBLIC
+│       │   │   │
+│       │   │   └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│       │   │         rule: "temp index exists before columns, partitioning, and partial"
+│       │   │         rule: "index-column added to index after temp index exists"
+│       │   │
+│       │   └── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}
+│       │       │ ABSENT → PUBLIC
+│       │       │
+│       │       └── • Precedence dependency from DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│       │             rule: "temp index exists before columns, partitioning, and partial"
+│       │             rule: "index-column added to index after temp index exists"
+│       │
+│       ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│       │   │
+│       │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│       │         ABSENT → DELETE_ONLY
+│       │
+│       └── • 14 Mutation operations
+│           │
+│           ├── • MakeDroppedColumnDeleteAndWriteOnly
+│           │     ColumnID: 2
+│           │     TableID: 104
+│           │
+│           ├── • LogEvent
+│           │     Element:
+│           │       Column:
+│           │         columnId: 2
+│           │         pgAttributeNum: 2
+│           │         tableId: 104
+│           │     EventBase:
+│           │       Authorization:
+│           │         UserName: root
+│           │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│           │       StatementTag: ALTER TABLE
+│           │       TargetMetadata:
+│           │         SourceElementID: 1
+│           │         SubWorkID: 1
+│           │     TargetStatus: 1
+│           │
+│           ├── • SetColumnName
+│           │     ColumnID: 2
+│           │     Name: crdb_internal_column_2_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeDroppedColumnDeleteAndWriteOnly
+│           │     ColumnID: 4
+│           │     TableID: 104
+│           │
+│           ├── • LogEvent
+│           │     Element:
+│           │       Column:
+│           │         columnId: 4
+│           │         isInaccessible: true
+│           │         pgAttributeNum: 4
+│           │         tableId: 104
+│           │     EventBase:
+│           │       Authorization:
+│           │         UserName: root
+│           │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│           │       StatementTag: ALTER TABLE
+│           │       TargetMetadata:
+│           │         SourceElementID: 1
+│           │         SubWorkID: 1
+│           │     TargetStatus: 1
+│           │
+│           ├── • SetColumnName
+│           │     ColumnID: 4
+│           │     Name: crdb_internal_column_4_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeDroppedNonPrimaryIndexDeleteAndWriteOnly
+│           │     IndexID: 2
+│           │     TableID: 104
+│           │
+│           ├── • SetIndexName
+│           │     IndexID: 2
+│           │     Name: crdb_internal_index_2_name_placeholder
+│           │     TableID: 104
+│           │
+│           ├── • MakeAddedIndexBackfilling
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 3
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 104
+│           │       TemporaryIndexID: 4
+│           │
+│           ├── • MakeAddedTempIndexDeleteOnly
+│           │     Index:
+│           │       ConstraintID: 1
+│           │       IndexID: 4
+│           │       IsUnique: true
+│           │       SourceIndexID: 1
+│           │       TableID: 104
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 1
+│           │     IndexID: 4
+│           │     TableID: 104
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 3
+│           │     IndexID: 4
+│           │     Kind: 2
+│           │     TableID: 104
+│           │
+│           ├── • AddColumnToIndex
+│           │     ColumnID: 1
+│           │     IndexID: 3
+│           │     TableID: 104
+│           │
+│           └── • AddColumnToIndex
+│                 ColumnID: 3
+│                 IndexID: 3
+│                 Kind: 2
+│                 TableID: 104
+│
+├── • PreCommitPhase
+│   │
+│   └── • Stage 1 of 1 in PreCommitPhase
+│       │
+│       └── • 2 Mutation operations
+│           │
+│           ├── • SetJobStateOnDescriptor
+│           │     DescriptorID: 104
+│           │     Initialize: true
+│           │
+│           └── • CreateSchemaChangerJob
+│                 Authorization:
+│                   UserName: root
+│                 DescriptorIDs:
+│                 - 104
+│                 JobID: 1
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
+│                 Statements:
+│                 - statement: ALTER TABLE t DROP COLUMN j CASCADE
+│                   redactedstatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│                   statementtag: ALTER TABLE
+│
+├── • PostCommitPhase
+│   │
+│   ├── • Stage 1 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│   │   │   │
+│   │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │       │ DELETE_ONLY → WRITE_ONLY
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+│   │   │       │     rule: "index-column added to index before temp index receives writes"
+│   │   │       │
+│   │   │       └── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}
+│   │   │             rule: "index-column added to index before temp index receives writes"
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       │     IndexID: 4
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 2 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │       │ BACKFILL_ONLY → BACKFILLED
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       └── • Precedence dependency from WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │             rule: "temp index is WRITE_ONLY before backfill"
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • BackfillIndex
+│   │             IndexID: 3
+│   │             SourceIndexID: 1
+│   │             TableID: 104
+│   │
+│   ├── • Stage 3 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         BACKFILLED → DELETE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfillingIndexDeleteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
+│   │
+│   ├── • Stage 4 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         DELETE_ONLY → MERGE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfilledIndexMerging
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 5 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGE_ONLY → MERGED
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • MergeIndex
+│   │             BackfilledIndexID: 3
+│   │             TableID: 104
+│   │             TemporaryIndexID: 4
+│   │
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
+│       │
+│       ├── • 1 element transitioning toward PUBLIC
+│       │   │
+│       │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │         WRITE_ONLY → VALIDATED
+│       │
+│       └── • 1 Validation operation
+│           │
+│           └── • ValidateUniqueIndex
+│                 IndexID: 3
+│                 TableID: 104
+│
+└── • PostCommitNonRevertiblePhase
+    │
+    ├── • Stage 1 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 11 elements transitioning toward ABSENT
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 2}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 4}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │     PUBLIC → WRITE_ONLY
+    │   │   │
+    │   │   ├── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │         VALIDATED → DELETE_ONLY
+    │   │
+    │   ├── • 2 elements transitioning toward PUBLIC
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+    │   │   │   │ VALIDATED → PUBLIC
+    │   │   │   │
+    │   │   │   ├── • SameStagePrecedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │   │     rule: "primary index swap"
+    │   │   │   │
+    │   │   │   └── • SameStagePrecedence dependency from PUBLIC IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+    │   │   │         rule: "index named right before index becomes public"
+    │   │   │
+    │   │   └── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+    │   │       │ ABSENT → PUBLIC
+    │   │       │
+    │   │       └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+    │   │             rule: "index existence precedes index name and comment"
+    │   │
+    │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+    │   │   │
+    │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+    │   │         WRITE_ONLY → TRANSIENT_DELETE_ONLY
+    │   │
+    │   └── • 16 Mutation operations
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 4
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedPrimaryIndexDeleteAndWriteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 1
+    │       │     Name: crdb_internal_index_1_name_placeholder
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 3
+    │       │     Name: t_pkey
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 4
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 2
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     Ordinal: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeAddedPrimaryIndexPublic
+    │       │     EventBase:
+    │       │       Authorization:
+    │       │         UserName: root
+    │       │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+    │       │       StatementTag: ALTER TABLE
+    │       │       TargetMetadata:
+    │       │         SourceElementID: 1
+    │       │         SubWorkID: 1
+    │       │     IndexID: 3
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 4
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 2
+    │       │     Ordinal: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 2
+    │       │     Kind: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending
+    │
+    ├── • Stage 2 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 1 element transitioning toward ABSENT
+    │   │   │
+    │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │         WRITE_ONLY → DELETE_ONLY
+    │   │
+    │   └── • 3 Mutation operations
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 3 of 3 with 9 MutationType ops pending
+    │
+    └── • Stage 3 of 3 in PostCommitNonRevertiblePhase
+        │
+        ├── • 6 elements transitioning toward ABSENT
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 2}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │         rule: "indexes containing columns reach absent before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 4}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 4}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │   │         rule: "indexes containing columns reach absent before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 4}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │   │         rule: "temp indexes reach absent at the same time as other indexes"
+        │   │
+        │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │       │ DELETE_ONLY → ABSENT
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_expr_k_idx, IndexID: 2}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │             rule: "temp indexes reach absent at the same time as other indexes"
+        │
+        ├── • 1 element transitioning toward TRANSIENT_ABSENT
+        │   │
+        │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │         TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT
+        │
+        └── • 11 Mutation operations
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 1
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     IndexID: 1
+            │     TableID: 104
+            │
+            ├── • LogEvent
+            │     Element:
+            │       SecondaryIndex:
+            │         indexId: 2
+            │         tableId: 104
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TargetStatus: 1
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 2
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 2
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 2
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 4
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • RemoveJobStateFromDescriptor
+            │     DescriptorID: 104
+            │     JobID: 1
+            │
+            └── • UpdateSchemaChangerJob
+                  IsNonCancelable: true
+                  JobID: 1
+                  RunningStatus: all stages completed
diff --git a/pkg/sql/schemachanger/testdata/explain_verbose/drop_multiple_columns_separate_statements.1 b/pkg/sql/schemachanger/testdata/explain_verbose/drop_multiple_columns_separate_statements.1
new file mode 100644
index 000000000000..152b7878543b
--- /dev/null
+++ b/pkg/sql/schemachanger/testdata/explain_verbose/drop_multiple_columns_separate_statements.1
@@ -0,0 +1,660 @@
+/* setup */
+create table t (i int primary key, j int, k int default 32 on update 42, index((j+1), k));
+
+/* test */
+alter table t drop column j cascade;
+EXPLAIN (ddl, verbose) alter table t drop column k cascade;
+----
+• Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE; ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹k› CASCADE; 
+│
+├── • StatementPhase
+│   │
+│   └── • Stage 1 of 1 in StatementPhase
+│       │
+│       ├── • 2 elements transitioning toward ABSENT
+│       │   │
+│       │   ├── • Column:{DescID: 104, ColumnID: 3}
+│       │   │     PUBLIC → WRITE_ONLY
+│       │   │
+│       │   └── • ColumnName:{DescID: 104, Name: k, ColumnID: 3}
+│       │       │ PUBLIC → ABSENT
+│       │       │
+│       │       └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 3}
+│       │             rule: "column dependents removed after column no longer public"
+│       │
+│       └── • 3 Mutation operations
+│           │
+│           ├── • MakeDroppedColumnDeleteAndWriteOnly
+│           │     ColumnID: 3
+│           │     TableID: 104
+│           │
+│           ├── • LogEvent
+│           │     Element:
+│           │       Column:
+│           │         columnId: 3
+│           │         pgAttributeNum: 3
+│           │         tableId: 104
+│           │     EventBase:
+│           │       Authorization:
+│           │         UserName: root
+│           │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹k› CASCADE
+│           │       StatementTag: ALTER TABLE
+│           │       TargetMetadata:
+│           │         SourceElementID: 1
+│           │         StatementID: 1
+│           │         SubWorkID: 1
+│           │     TargetStatus: 1
+│           │
+│           └── • SetColumnName
+│                 ColumnID: 3
+│                 Name: crdb_internal_column_3_name_placeholder
+│                 TableID: 104
+│
+├── • PreCommitPhase
+│   │
+│   └── • Stage 1 of 1 in PreCommitPhase
+│       │
+│       └── • 2 Mutation operations
+│           │
+│           ├── • SetJobStateOnDescriptor
+│           │     DescriptorID: 104
+│           │     Initialize: true
+│           │
+│           └── • CreateSchemaChangerJob
+│                 Authorization:
+│                   UserName: root
+│                 DescriptorIDs:
+│                 - 104
+│                 JobID: 1
+│                 RunningStatus: PostCommitPhase stage 1 of 7 with 1 MutationType op pending
+│                 Statements:
+│                 - statement: ALTER TABLE t DROP COLUMN j CASCADE
+│                   redactedstatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+│                   statementtag: ALTER TABLE
+│                 - statement: ALTER TABLE t DROP COLUMN k CASCADE
+│                   redactedstatement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹k› CASCADE
+│                   statementtag: ALTER TABLE
+│
+├── • PostCommitPhase
+│   │
+│   ├── • Stage 1 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+│   │   │   │
+│   │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │       │ DELETE_ONLY → WRITE_ONLY
+│   │   │       │
+│   │   │       └── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
+│   │   │             rule: "index-column added to index before temp index receives writes"
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeAddedIndexDeleteAndWriteOnly
+│   │       │     IndexID: 4
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 2 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 2 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │       │ BACKFILL_ONLY → BACKFILLED
+│   │   │       │
+│   │   │       ├── • Precedence dependency from PUBLIC IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
+│   │   │       │     rule: "index-column added to index before index is backfilled"
+│   │   │       │
+│   │   │       └── • Precedence dependency from WRITE_ONLY TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+│   │   │             rule: "temp index is WRITE_ONLY before backfill"
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • BackfillIndex
+│   │             IndexID: 3
+│   │             SourceIndexID: 1
+│   │             TableID: 104
+│   │
+│   ├── • Stage 3 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         BACKFILLED → DELETE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfillingIndexDeleteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 4 of 7 with 1 MutationType op pending
+│   │
+│   ├── • Stage 4 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         DELETE_ONLY → MERGE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeBackfilledIndexMerging
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 5 of 7 with 1 BackfillType op pending
+│   │
+│   ├── • Stage 5 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGE_ONLY → MERGED
+│   │   │
+│   │   └── • 1 Backfill operation
+│   │       │
+│   │       └── • MergeIndex
+│   │             BackfilledIndexID: 3
+│   │             TableID: 104
+│   │             TemporaryIndexID: 4
+│   │
+│   ├── • Stage 6 of 7 in PostCommitPhase
+│   │   │
+│   │   ├── • 1 element transitioning toward PUBLIC
+│   │   │   │
+│   │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│   │   │         MERGED → WRITE_ONLY
+│   │   │
+│   │   └── • 3 Mutation operations
+│   │       │
+│   │       ├── • MakeMergedIndexWriteOnly
+│   │       │     IndexID: 3
+│   │       │     TableID: 104
+│   │       │
+│   │       ├── • SetJobStateOnDescriptor
+│   │       │     DescriptorID: 104
+│   │       │
+│   │       └── • UpdateSchemaChangerJob
+│   │             JobID: 1
+│   │             RunningStatus: PostCommitPhase stage 7 of 7 with 1 ValidationType op pending
+│   │
+│   └── • Stage 7 of 7 in PostCommitPhase
+│       │
+│       ├── • 1 element transitioning toward PUBLIC
+│       │   │
+│       │   └── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+│       │         WRITE_ONLY → VALIDATED
+│       │
+│       └── • 1 Validation operation
+│           │
+│           └── • ValidateUniqueIndex
+│                 IndexID: 3
+│                 TableID: 104
+│
+└── • PostCommitNonRevertiblePhase
+    │
+    ├── • Stage 1 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 14 elements transitioning toward ABSENT
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 3}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 2}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • Column:{DescID: 104, ColumnID: 4}
+    │   │   │     WRITE_ONLY → DELETE_ONLY
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │     PUBLIC → WRITE_ONLY
+    │   │   │
+    │   │   ├── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+    │   │   │   │ PUBLIC → ABSENT
+    │   │   │   │
+    │   │   │   ├── • Precedence dependency from DELETE_ONLY SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │   │     rule: "secondary index in DELETE_ONLY before removing columns"
+    │   │   │   │
+    │   │   │   └── • Precedence dependency from VALIDATED SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │         rule: "index no longer public before dependents removed"
+    │   │   │
+    │   │   ├── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+    │   │   │     VALIDATED → DELETE_ONLY
+    │   │   │
+    │   │   ├── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 3}
+    │   │   │     PUBLIC → ABSENT
+    │   │   │
+    │   │   └── • IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 4}
+    │   │         PUBLIC → ABSENT
+    │   │
+    │   ├── • 2 elements transitioning toward PUBLIC
+    │   │   │
+    │   │   ├── • PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+    │   │   │   │ VALIDATED → PUBLIC
+    │   │   │   │
+    │   │   │   ├── • SameStagePrecedence dependency from VALIDATED PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │   │   │     rule: "primary index swap"
+    │   │   │   │
+    │   │   │   └── • SameStagePrecedence dependency from PUBLIC IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+    │   │   │         rule: "index named right before index becomes public"
+    │   │   │
+    │   │   └── • IndexName:{DescID: 104, Name: t_pkey, IndexID: 3}
+    │   │       │ ABSENT → PUBLIC
+    │   │       │
+    │   │       └── • Precedence dependency from BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 1, TemporaryIndexID: 4, SourceIndexID: 1}
+    │   │             rule: "index existence precedes index name and comment"
+    │   │
+    │   ├── • 1 element transitioning toward TRANSIENT_ABSENT
+    │   │   │
+    │   │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+    │   │         WRITE_ONLY → TRANSIENT_DELETE_ONLY
+    │   │
+    │   └── • 19 Mutation operations
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 3
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedColumnDeleteOnly
+    │       │     ColumnID: 4
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedPrimaryIndexDeleteAndWriteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 1
+    │       │     Name: crdb_internal_index_1_name_placeholder
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 3
+    │       │     Kind: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 4
+    │       │     Kind: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetIndexName
+    │       │     IndexID: 3
+    │       │     Name: t_pkey
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 4
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 2
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 1
+    │       │     Kind: 2
+    │       │     Ordinal: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • MakeAddedPrimaryIndexPublic
+    │       │     EventBase:
+    │       │       Authorization:
+    │       │         UserName: root
+    │       │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+    │       │       StatementTag: ALTER TABLE
+    │       │       TargetMetadata:
+    │       │         SourceElementID: 1
+    │       │         SubWorkID: 1
+    │       │     IndexID: 3
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 4
+    │       │     IndexID: 2
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 3
+    │       │     IndexID: 2
+    │       │     Ordinal: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • RemoveColumnFromIndex
+    │       │     ColumnID: 1
+    │       │     IndexID: 2
+    │       │     Kind: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 2 of 3 with 1 MutationType op pending
+    │
+    ├── • Stage 2 of 3 in PostCommitNonRevertiblePhase
+    │   │
+    │   ├── • 1 element transitioning toward ABSENT
+    │   │   │
+    │   │   └── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+    │   │         WRITE_ONLY → DELETE_ONLY
+    │   │
+    │   └── • 3 Mutation operations
+    │       │
+    │       ├── • MakeDroppedIndexDeleteOnly
+    │       │     IndexID: 1
+    │       │     TableID: 104
+    │       │
+    │       ├── • SetJobStateOnDescriptor
+    │       │     DescriptorID: 104
+    │       │
+    │       └── • UpdateSchemaChangerJob
+    │             IsNonCancelable: true
+    │             JobID: 1
+    │             RunningStatus: PostCommitNonRevertiblePhase stage 3 of 3 with 12 MutationType ops
+    │               pending
+    │
+    └── • Stage 3 of 3 in PostCommitNonRevertiblePhase
+        │
+        ├── • 10 elements transitioning toward ABSENT
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 3}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: k, ColumnID: 3}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │   │     rule: "indexes containing columns reach absent before column"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │   │         rule: "indexes containing columns reach absent before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 3}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 3}
+        │   │   │     rule: "column dependents removed after column no longer public"
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnDefaultExpression:{DescID: 104, ColumnID: 3}
+        │   │   │     rule: "column type dependents removed right before column type"
+        │   │   │
+        │   │   └── • SameStagePrecedence dependency from ABSENT ColumnOnUpdateExpression:{DescID: 104, ColumnID: 3}
+        │   │         rule: "column type dependents removed right before column type"
+        │   │
+        │   ├── • ColumnDefaultExpression:{DescID: 104, ColumnID: 3}
+        │   │     PUBLIC → ABSENT
+        │   │
+        │   ├── • ColumnOnUpdateExpression:{DescID: 104, ColumnID: 3}
+        │   │     PUBLIC → ABSENT
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 2}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │   │     rule: "indexes containing columns reach absent before column"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: j, ColumnID: 2}
+        │   │         rule: "dependents removed before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 2}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • Column:{DescID: 104, ColumnID: 4}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • SameStagePrecedence dependency from ABSENT ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+        │   │   │     rule: "dependents removed before column"
+        │   │   │     rule: "column type removed right before column when not dropping relation"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │   │   │     rule: "indexes containing columns reach absent before column"
+        │   │   │
+        │   │   └── • Precedence dependency from ABSENT ColumnName:{DescID: 104, Name: crdb_internal_idx_expr, ColumnID: 4}
+        │   │         rule: "dependents removed before column"
+        │   │
+        │   ├── • ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 4}
+        │   │   │ PUBLIC → ABSENT
+        │   │   │
+        │   │   └── • Precedence dependency from WRITE_ONLY Column:{DescID: 104, ColumnID: 4}
+        │   │         rule: "column dependents removed after column no longer public"
+        │   │
+        │   ├── • PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+        │   │   │ DELETE_ONLY → ABSENT
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
+        │   │   │     rule: "dependents removed before index"
+        │   │   │
+        │   │   └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │   │         rule: "temp indexes reach absent at the same time as other indexes"
+        │   │
+        │   └── • SecondaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 0}
+        │       │ DELETE_ONLY → ABSENT
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 4, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 3, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 2}
+        │       │     rule: "secondary index columns removed before removing the index"
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       ├── • Precedence dependency from ABSENT IndexName:{DescID: 104, Name: t_expr_k_idx, IndexID: 2}
+        │       │     rule: "dependents removed before index"
+        │       │
+        │       └── • SameStagePrecedence dependency from TRANSIENT_ABSENT TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │             rule: "temp indexes reach absent at the same time as other indexes"
+        │
+        ├── • 1 element transitioning toward TRANSIENT_ABSENT
+        │   │
+        │   └── • TemporaryIndex:{DescID: 104, IndexID: 4, SourceIndexID: 1}
+        │         TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT
+        │
+        └── • 14 Mutation operations
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 4
+            │     TableID: 104
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 1
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     IndexID: 1
+            │     TableID: 104
+            │
+            ├── • LogEvent
+            │     Element:
+            │       SecondaryIndex:
+            │         indexId: 2
+            │         tableId: 104
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TargetStatus: 1
+            │
+            ├── • CreateGcJobForIndex
+            │     IndexID: 2
+            │     StatementForDropJob:
+            │       Statement: ALTER TABLE defaultdb.public.t DROP COLUMN j CASCADE
+            │     TableID: 104
+            │
+            ├── • MakeIndexAbsent
+            │     IndexID: 2
+            │     TableID: 104
+            │
+            ├── • RemoveColumnDefaultExpression
+            │     ColumnID: 3
+            │     TableID: 104
+            │
+            ├── • RemoveColumnOnUpdateExpression
+            │     ColumnID: 3
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 2
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 4
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹j› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • MakeColumnAbsent
+            │     ColumnID: 3
+            │     EventBase:
+            │       Authorization:
+            │         UserName: root
+            │       Statement: ALTER TABLE ‹defaultdb›.‹public›.‹t› DROP COLUMN ‹k› CASCADE
+            │       StatementTag: ALTER TABLE
+            │       TargetMetadata:
+            │         SourceElementID: 1
+            │         StatementID: 1
+            │         SubWorkID: 1
+            │     TableID: 104
+            │
+            ├── • RemoveJobStateFromDescriptor
+            │     DescriptorID: 104
+            │     JobID: 1
+            │
+            └── • UpdateSchemaChangerJob
+                  IsNonCancelable: true
+                  JobID: 1
+                  RunningStatus: all stages completed