scplan: make EXPLAIN target output stable

This commit does not make any functional changes. It merely ensures that
the diagrams generated by an EXPLAIN (DDL) statement list the schema
change targets in a predefined order: first the to-public targets, then
the transient targets, and finally the to-absent targets.

This helps readability and makes the declarative schema changer
data-driven test output more stable.

Release justification: low-impact, test-only change
Release note: None

pkg/sql/schemachanger/scplan/plan_explain.go

@@ -190,8 +190,11 @@ func (p Plan) explainTargets(s scstage.Stage, sn treeprinter.Node, style treepri
 	// Generate format string for printing element status transition.
 	fmtCompactTransition := fmt.Sprintf("%%-%ds → %%-%ds %%s", beforeMaxLen, afterMaxLen)
 	// Go over each target grouping.
-	targetTypeMap.ForEach(func(key, numTransitions int) {
-		ts := scpb.TargetStatus(key)
+	for _, ts := range []scpb.TargetStatus{scpb.ToPublic, scpb.Transient, scpb.ToAbsent} {
+		numTransitions := targetTypeMap.GetDefault(int(ts))
+		if numTransitions == 0 {
+			continue
+		}
 		plural := "s"
 		if numTransitions == 1 {
 			plural = ""
@@ -233,7 +236,7 @@ func (p Plan) explainTargets(s scstage.Stage, sn treeprinter.Node, style treepri
 				}
 			}
 		}
-	})
+	}
 	return nil
 }
 

pkg/sql/schemachanger/testdata/explain/add_column

@@ -87,10 +87,6 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
  │              └── ValidateUniqueIndex {"IndexID":2,"TableID":106}
  └── PostCommitNonRevertiblePhase
       ├── Stage 1 of 3 in PostCommitNonRevertiblePhase
-      │    ├── 3 elements transitioning toward ABSENT
-      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 1}
-      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
-      │    │    └── PUBLIC     → ABSENT                IndexName:{DescID: 106, Name: tbl_pkey, IndexID: 1}
       │    ├── 3 elements transitioning toward PUBLIC
       │    │    ├── WRITE_ONLY → PUBLIC                Column:{DescID: 106, ColumnID: 2}
       │    │    ├── VALIDATED  → PUBLIC                PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 2, TemporaryIndexID: 3, SourceIndexID: 1}
@@ -99,6 +95,10 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
       │    │    ├── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 106, IndexID: 3, ConstraintID: 3, SourceIndexID: 1}
       │    │    ├── PUBLIC     → TRANSIENT_ABSENT      IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 3}
       │    │    └── PUBLIC     → TRANSIENT_ABSENT      IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 3}
+      │    ├── 3 elements transitioning toward ABSENT
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 1}
+      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+      │    │    └── PUBLIC     → ABSENT                IndexName:{DescID: 106, Name: tbl_pkey, IndexID: 1}
       │    └── 9 Mutation operations
       │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":106}
       │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":106}
@@ -110,10 +110,10 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
       │         ├── 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}
       │    ├── 1 element transitioning toward TRANSIENT_ABSENT
       │    │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 106, IndexID: 3, ConstraintID: 3, SourceIndexID: 1}
+      │    ├── 1 element transitioning toward ABSENT
+      │    │    └── WRITE_ONLY            → DELETE_ONLY      PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
       │    └── 5 Mutation operations
       │         ├── MakeDroppedIndexDeleteOnly {"IndexID":1,"TableID":106}
       │         ├── CreateGcJobForIndex {"IndexID":3,"TableID":106}

pkg/sql/schemachanger/testdata/explain/add_column_default_seq

@@ -93,10 +93,6 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
  │              └── ValidateUniqueIndex {"IndexID":2,"TableID":106}
  └── PostCommitNonRevertiblePhase
       ├── Stage 1 of 3 in PostCommitNonRevertiblePhase
-      │    ├── 3 elements transitioning toward ABSENT
-      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 1}
-      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
-      │    │    └── PUBLIC     → ABSENT                IndexName:{DescID: 106, Name: tbl_pkey, IndexID: 1}
       │    ├── 3 elements transitioning toward PUBLIC
       │    │    ├── WRITE_ONLY → PUBLIC                Column:{DescID: 106, ColumnID: 2}
       │    │    ├── VALIDATED  → PUBLIC                PrimaryIndex:{DescID: 106, IndexID: 2, ConstraintID: 2, TemporaryIndexID: 3, SourceIndexID: 1}
@@ -105,6 +101,10 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
       │    │    ├── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 106, IndexID: 3, ConstraintID: 3, SourceIndexID: 1}
       │    │    ├── PUBLIC     → TRANSIENT_ABSENT      IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 3}
       │    │    └── PUBLIC     → TRANSIENT_ABSENT      IndexColumn:{DescID: 106, ColumnID: 2, IndexID: 3}
+      │    ├── 3 elements transitioning toward ABSENT
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 106, ColumnID: 1, IndexID: 1}
+      │    │    ├── PUBLIC     → WRITE_ONLY            PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
+      │    │    └── PUBLIC     → ABSENT                IndexName:{DescID: 106, Name: tbl_pkey, IndexID: 1}
       │    └── 10 Mutation operations
       │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":106}
       │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":106}
@@ -117,10 +117,10 @@ Schema change plan for ALTER TABLE ‹db›.‹public›.‹tbl› ADD COLUMN 
       │         ├── SetJobStateOnDescriptor {"DescriptorID":107}
       │         └── 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}
       │    ├── 1 element transitioning toward TRANSIENT_ABSENT
       │    │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT TemporaryIndex:{DescID: 106, IndexID: 3, ConstraintID: 3, SourceIndexID: 1}
+      │    ├── 1 element transitioning toward ABSENT
+      │    │    └── WRITE_ONLY            → DELETE_ONLY      PrimaryIndex:{DescID: 106, IndexID: 1, ConstraintID: 1}
       │    └── 6 Mutation operations
       │         ├── MakeDroppedIndexDeleteOnly {"IndexID":1,"TableID":106}
       │         ├── CreateGcJobForIndex {"IndexID":3,"TableID":106}

pkg/sql/schemachanger/testdata/explain/alter_table_add_primary_key_drop_rowid

@@ -7,9 +7,6 @@ EXPLAIN (ddl) alter table t add primary key (a);
 Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› ADD PRIMARY KEY (‹a›); 
  ├── 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: rowid, ColumnID: 2}
  │         ├── 2 elements transitioning toward PUBLIC
  │         │    ├── ABSENT → BACKFILL_ONLY PrimaryIndex:{DescID: 104, IndexID: 4, ConstraintID: 4, TemporaryIndexID: 5, SourceIndexID: 2}
  │         │    └── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
@@ -20,6 +17,9 @@ Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› ADD PRIM
  │         │    ├── ABSENT → DELETE_ONLY   TemporaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 3, SourceIndexID: 1}
  │         │    ├── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
  │         │    └── ABSENT → PUBLIC        IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 3}
+ │         ├── 2 elements transitioning toward ABSENT
+ │         │    ├── PUBLIC → WRITE_ONLY    Column:{DescID: 104, ColumnID: 2}
+ │         │    └── PUBLIC → ABSENT        ColumnName:{DescID: 104, Name: rowid, ColumnID: 2}
  │         └── 11 Mutation operations
  │              ├── MakeDroppedColumnDeleteAndWriteOnly {"ColumnID":2,"TableID":104}
  │              ├── LogEvent {"TargetStatus":1}
@@ -82,14 +82,14 @@ Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› ADD PRIM
  │    │    └── 1 Validation operation
  │    │         └── ValidateUniqueIndex {"IndexID":2,"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}
  │    │    ├── 4 elements transitioning toward TRANSIENT_ABSENT
  │    │    │    ├── VALIDATED → PUBLIC      PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 2, TemporaryIndexID: 3, SourceIndexID: 1}
  │    │    │    ├── ABSENT    → PUBLIC      IndexName:{DescID: 104, Name: t_pkey, IndexID: 2}
  │    │    │    ├── ABSENT    → DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 5, SourceIndexID: 2}
  │    │    │    └── ABSENT    → PUBLIC      IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 5}
+ │    │    ├── 2 elements transitioning toward ABSENT
+ │    │    │    ├── PUBLIC    → VALIDATED   PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+ │    │    │    └── PUBLIC    → ABSENT      IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
  │    │    └── 8 Mutation operations
  │    │         ├── MakeDroppedPrimaryIndexDeleteAndWriteOnly {"IndexID":1,"TableID":104}
  │    │         ├── SetIndexName {"IndexID":1,"Name":"crdb_internal_in...","TableID":104}
@@ -144,17 +144,17 @@ Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› ADD PRIM
  │              └── ValidateUniqueIndex {"IndexID":4,"TableID":104}
  └── PostCommitNonRevertiblePhase
       ├── Stage 1 of 4 in PostCommitNonRevertiblePhase
-      │    ├── 4 elements transitioning toward ABSENT
-      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 2}
-      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
-      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
-      │    │    └── VALIDATED  → DELETE_ONLY           PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
       │    ├── 5 elements transitioning toward TRANSIENT_ABSENT
       │    │    ├── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 3, SourceIndexID: 1}
       │    │    ├── PUBLIC     → TRANSIENT_ABSENT      IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 3}
       │    │    ├── PUBLIC     → TRANSIENT_ABSENT      IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 3}
       │    │    ├── WRITE_ONLY → TRANSIENT_DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 5, SourceIndexID: 2}
       │    │    └── PUBLIC     → TRANSIENT_ABSENT      IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 5}
+      │    ├── 4 elements transitioning toward ABSENT
+      │    │    ├── WRITE_ONLY → DELETE_ONLY           Column:{DescID: 104, ColumnID: 2}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 1}
+      │    │    ├── PUBLIC     → ABSENT                IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 1}
+      │    │    └── VALIDATED  → DELETE_ONLY           PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
       │    └── 6 Mutation operations
       │         ├── MakeDroppedColumnDeleteOnly {"ColumnID":2,"TableID":104}
       │         ├── MakeDroppedIndexDeleteOnly {"IndexID":3,"TableID":104}
@@ -163,8 +163,6 @@ Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› ADD PRIM
       │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
       │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
       ├── Stage 2 of 4 in PostCommitNonRevertiblePhase
-      │    ├── 1 element transitioning toward ABSENT
-      │    │    └── DELETE_ONLY           → ABSENT               PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
       │    ├── 2 elements transitioning toward PUBLIC
       │    │    ├── VALIDATED             → PUBLIC               PrimaryIndex:{DescID: 104, IndexID: 4, ConstraintID: 4, TemporaryIndexID: 5, SourceIndexID: 2}
       │    │    └── ABSENT                → PUBLIC               IndexName:{DescID: 104, Name: t_pkey, IndexID: 4}
@@ -175,6 +173,8 @@ Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› ADD PRIM
       │    │    ├── PUBLIC                → TRANSIENT_ABSENT     IndexColumn:{DescID: 104, ColumnID: 2, IndexID: 2}
       │    │    ├── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT     TemporaryIndex:{DescID: 104, IndexID: 3, ConstraintID: 3, SourceIndexID: 1}
       │    │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT     TemporaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 5, SourceIndexID: 2}
+      │    ├── 1 element transitioning toward ABSENT
+      │    │    └── DELETE_ONLY           → ABSENT               PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
       │    └── 12 Mutation operations
       │         ├── CreateGcJobForIndex {"IndexID":1,"TableID":104}
       │         ├── MakeIndexAbsent {"IndexID":1,"TableID":104}
@@ -196,12 +196,12 @@ Schema change plan for ALTER TABLE ‹defaultdb›.‹public›.‹t› ADD PRIM
       │         ├── SetJobStateOnDescriptor {"DescriptorID":104}
       │         └── UpdateSchemaChangerJob {"IsNonCancelable":true,"RunningStatus":"PostCommitNonRev..."}
       └── Stage 4 of 4 in PostCommitNonRevertiblePhase
+           ├── 1 element transitioning toward TRANSIENT_ABSENT
+           │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 2, TemporaryIndexID: 3, SourceIndexID: 1}
            ├── 3 elements transitioning toward ABSENT
            │    ├── DELETE_ONLY           → ABSENT           Column:{DescID: 104, ColumnID: 2}
            │    ├── PUBLIC                → ABSENT           ColumnType:{DescID: 104, ColumnFamilyID: 0, ColumnID: 2}
            │    └── PUBLIC                → ABSENT           ColumnDefaultExpression:{DescID: 104, ColumnID: 2}
-           ├── 1 element transitioning toward TRANSIENT_ABSENT
-           │    └── TRANSIENT_DELETE_ONLY → TRANSIENT_ABSENT PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 2, TemporaryIndexID: 3, SourceIndexID: 1}
            └── 6 Mutation operations
                 ├── CreateGcJobForIndex {"IndexID":2,"TableID":104}
                 ├── MakeIndexAbsent {"IndexID":2,"TableID":104}

pkg/sql/schemachanger/testdata/explain/alter_table_add_primary_key_drop_rowid.rollback_10_of_15

@@ -8,6 +8,11 @@ EXPLAIN (ddl) rollback at post-commit stage 10 of 15;
 Schema change plan for rolling back ALTER TABLE ‹defaultdb›.public.‹t› ADD PRIMARY KEY (‹a›); 
  └── PostCommitNonRevertiblePhase
       ├── Stage 1 of 3 in PostCommitNonRevertiblePhase
+      │    ├── 4 elements transitioning toward PUBLIC
+      │    │    ├── WRITE_ONLY    → PUBLIC      Column:{DescID: 104, ColumnID: 2}
+      │    │    ├── ABSENT        → PUBLIC      ColumnName:{DescID: 104, Name: rowid, ColumnID: 2}
+      │    │    ├── VALIDATED     → PUBLIC      PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
+      │    │    └── ABSENT        → PUBLIC      IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
       │    ├── 11 elements transitioning toward ABSENT
       │    │    ├── PUBLIC        → WRITE_ONLY  PrimaryIndex:{DescID: 104, IndexID: 2, ConstraintID: 2, TemporaryIndexID: 3, SourceIndexID: 1}
       │    │    ├── PUBLIC        → ABSENT      IndexName:{DescID: 104, Name: t_pkey, IndexID: 2}
@@ -20,11 +25,6 @@ Schema change plan for rolling back ALTER TABLE ‹defaultdb›.public.‹t› A
       │    │    ├── PUBLIC        → ABSENT      IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 4}
       │    │    ├── WRITE_ONLY    → DELETE_ONLY TemporaryIndex:{DescID: 104, IndexID: 5, ConstraintID: 5, SourceIndexID: 2}
       │    │    └── PUBLIC        → ABSENT      IndexColumn:{DescID: 104, ColumnID: 1, IndexID: 5}
-      │    ├── 4 elements transitioning toward PUBLIC
-      │    │    ├── WRITE_ONLY    → PUBLIC      Column:{DescID: 104, ColumnID: 2}
-      │    │    ├── ABSENT        → PUBLIC      ColumnName:{DescID: 104, Name: rowid, ColumnID: 2}
-      │    │    ├── VALIDATED     → PUBLIC      PrimaryIndex:{DescID: 104, IndexID: 1, ConstraintID: 1}
-      │    │    └── ABSENT        → PUBLIC      IndexName:{DescID: 104, Name: t_pkey, IndexID: 1}
       │    └── 13 Mutation operations
       │         ├── SetColumnName {"ColumnID":2,"Name":"rowid","TableID":104}
       │         ├── SetIndexName {"IndexID":1,"Name":"t_pkey","TableID":104}