opt: give synthesized assignment cast columns descriptive names

Columns synthesized for assignment casts now have more descriptive
metadata names in the form `<target_column_name>_cast`. This is purely
an aesthetic change and has no effect on semantics.

Release note: None

pkg/sql/opt/exec/execbuilder/testdata/hash_sharded_index

@@ -19,16 +19,16 @@ vectorized: true
 │ auto commit
 │
 └── • render
-    │ columns: (column7, column1, check1)
+    │ columns: (crdb_internal_a_shard_11_cast, column1, check1)
     │ estimated row count: 2
-    │ render check1: column7 IN (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+    │ render check1: crdb_internal_a_shard_11_cast IN (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
     │ render column1: column1
-    │ render column7: column7
+    │ render crdb_internal_a_shard_11_cast: crdb_internal_a_shard_11_cast
     │
     └── • render
-        │ columns: (column7, column1)
+        │ columns: (crdb_internal_a_shard_11_cast, column1)
         │ estimated row count: 2
-        │ render column7: crdb_internal.assignment_cast(mod(fnv32(crdb_internal.datums_to_bytes(column1)), 11), NULL::INT4)
+        │ render crdb_internal_a_shard_11_cast: crdb_internal.assignment_cast(mod(fnv32(crdb_internal.datums_to_bytes(column1)), 11), NULL::INT4)
         │ render column1: column1
         │
         └── • values
@@ -53,17 +53,17 @@ vectorized: true
 │ auto commit
 │
 └── • render
-    │ columns: (column1, column9, rowid_default, check1)
+    │ columns: (column1, crdb_internal_a_shard_12_cast, rowid_default, check1)
     │ estimated row count: 2
-    │ render check1: column9 IN (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
+    │ render check1: crdb_internal_a_shard_12_cast IN (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
     │ render column1: column1
     │ render rowid_default: rowid_default
-    │ render column9: column9
+    │ render crdb_internal_a_shard_12_cast: crdb_internal_a_shard_12_cast
     │
     └── • render
-        │ columns: (column9, rowid_default, column1)
+        │ columns: (crdb_internal_a_shard_12_cast, rowid_default, column1)
         │ estimated row count: 2
-        │ render column9: crdb_internal.assignment_cast(mod(fnv32(crdb_internal.datums_to_bytes(column1)), 12), NULL::INT4)
+        │ render crdb_internal_a_shard_12_cast: crdb_internal.assignment_cast(mod(fnv32(crdb_internal.datums_to_bytes(column1)), 12), NULL::INT4)
         │ render rowid_default: unique_rowid()
         │ render column1: column1
         │

pkg/sql/opt/exec/explain/testdata/gists_tpce

@@ -349,7 +349,7 @@ explain(shape):
 │       │
 │       └── • lookup join (anti)
 │           │ table: status_type@status_type_pkey
-│           │ equality: (column62) = (st_id)
+│           │ equality: (th_st_id_cast) = (st_id)
 │           │ equality cols are key
 │           │
 │           └── • scan buffer
@@ -361,7 +361,7 @@ explain(shape):
         │
         └── • lookup join (anti)
             │ table: status_type@status_type_pkey
-            │ equality: (column127) = (st_id)
+            │ equality: (t_st_id_cast) = (st_id)
             │ equality cols are key
             │
             └── • scan buffer

pkg/sql/opt/norm/testdata/rules/fold_constants

@@ -832,15 +832,15 @@ INSERT INTO assn_cast (c, qc, i, s) VALUES (' ', 'foo', '1', 2)
 insert assn_cast
  ├── columns: <none>
  ├── insert-mapping:
- │    ├── column12:12 => c:1
- │    ├── column13:13 => qc:2
+ │    ├── c_cast:12 => c:1
+ │    ├── qc_cast:13 => qc:2
  │    ├── column3:10 => i:3
- │    ├── column14:14 => s:4
+ │    ├── s_cast:14 => s:4
  │    └── rowid_default:15 => rowid:5
  ├── cardinality: [0 - 0]
  ├── volatile, mutations
  └── values
-      ├── columns: column3:10!null column12:12!null column13:13!null column14:14!null rowid_default:15
+      ├── columns: column3:10!null c_cast:12!null qc_cast:13!null s_cast:14!null rowid_default:15
       ├── cardinality: [1 - 1]
       ├── volatile
       ├── key: ()
@@ -854,15 +854,15 @@ INSERT INTO assn_cast (c) VALUES ('foo')
 insert assn_cast
  ├── columns: <none>
  ├── insert-mapping:
- │    ├── column9:9 => c:1
+ │    ├── c_cast:9 => c:1
  │    ├── qc_default:10 => qc:2
  │    ├── i_default:11 => i:3
  │    ├── s_default:12 => s:4
  │    └── rowid_default:13 => rowid:5
  ├── cardinality: [0 - 0]
  ├── volatile, mutations
  └── values
-      ├── columns: column9:9 qc_default:10 i_default:11 s_default:12 rowid_default:13
+      ├── columns: c_cast:9 qc_default:10 i_default:11 s_default:12 rowid_default:13
       ├── cardinality: [1 - 1]
       ├── volatile
       ├── key: ()
@@ -882,15 +882,15 @@ INSERT INTO assn_cast(c) VALUES ($1)
 insert assn_cast
  ├── columns: <none>
  ├── insert-mapping:
- │    ├── column9:9 => c:1
+ │    ├── c_cast:9 => c:1
  │    ├── qc_default:10 => qc:2
  │    ├── i_default:11 => i:3
  │    ├── s_default:12 => s:4
  │    └── rowid_default:13 => rowid:5
  ├── cardinality: [0 - 0]
  ├── volatile, mutations, has-placeholder
  └── values
-      ├── columns: column9:9 qc_default:10 i_default:11 s_default:12 rowid_default:13
+      ├── columns: c_cast:9 qc_default:10 i_default:11 s_default:12 rowid_default:13
       ├── cardinality: [1 - 1]
       ├── volatile, has-placeholder
       ├── key: ()
@@ -913,12 +913,12 @@ insert assn_cast
  │    ├── c_default:10 => c:1
  │    ├── qc_default:11 => qc:2
  │    ├── i_default:12 => i:3
- │    ├── column9:9 => s:4
+ │    ├── s_cast:9 => s:4
  │    └── rowid_default:13 => rowid:5
  ├── cardinality: [0 - 0]
  ├── volatile, mutations
  └── values
-      ├── columns: column9:9!null c_default:10 qc_default:11 i_default:12 rowid_default:13
+      ├── columns: s_cast:9!null c_default:10 qc_default:11 i_default:12 rowid_default:13
       ├── cardinality: [1 - 1]
       ├── volatile
       ├── key: ()
@@ -935,12 +935,12 @@ insert assn_cast
  │    ├── c_default:10 => c:1
  │    ├── qc_default:11 => qc:2
  │    ├── i_default:12 => i:3
- │    ├── column9:9 => s:4
+ │    ├── s_cast:9 => s:4
  │    └── rowid_default:13 => rowid:5
  ├── cardinality: [0 - 0]
  ├── stable+volatile, mutations
  └── values
-      ├── columns: column9:9 c_default:10 qc_default:11 i_default:12 rowid_default:13
+      ├── columns: s_cast:9 c_default:10 qc_default:11 i_default:12 rowid_default:13
       ├── cardinality: [1 - 1]
       ├── stable+volatile
       ├── key: ()

pkg/sql/opt/norm/testdata/rules/project

@@ -1050,19 +1050,19 @@ INSERT INTO assn_cast (c, qc, i, s) VALUES (' ', 'foo', '1', 2), ('bar', 'baz',
 insert assn_cast
  ├── columns: <none>
  ├── insert-mapping:
- │    ├── column12:12 => c:1
- │    ├── column13:13 => qc:2
+ │    ├── c_cast:12 => c:1
+ │    ├── qc_cast:13 => qc:2
  │    ├── column3:10 => i:3
- │    ├── column14:14 => s:4
+ │    ├── s_cast:14 => s:4
  │    └── rowid_default:15 => rowid:5
  ├── cardinality: [0 - 0]
  ├── volatile, mutations
  └── project
-      ├── columns: rowid_default:15 column3:10!null column12:12 column13:13!null column14:14!null
+      ├── columns: rowid_default:15 column3:10!null c_cast:12 qc_cast:13!null s_cast:14!null
       ├── cardinality: [2 - 2]
       ├── volatile
       ├── values
-      │    ├── columns: column12:12 column13:13!null column3:10!null column14:14!null
+      │    ├── columns: c_cast:12 qc_cast:13!null column3:10!null s_cast:14!null
       │    ├── cardinality: [2 - 2]
       │    ├── immutable
       │    ├── ('', 'f', 1, '2')
@@ -1082,19 +1082,19 @@ INSERT INTO assn_cast (c, qc, i, s) VALUES (' ', 'foo', 1, 'bar'), ($1, $2, $3,
 insert assn_cast
  ├── columns: <none>
  ├── insert-mapping:
- │    ├── column12:12 => c:1
- │    ├── column13:13 => qc:2
+ │    ├── c_cast:12 => c:1
+ │    ├── qc_cast:13 => qc:2
  │    ├── column3:10 => i:3
  │    ├── column4:11 => s:4
  │    └── rowid_default:14 => rowid:5
  ├── cardinality: [0 - 0]
  ├── volatile, mutations, has-placeholder
  └── project
-      ├── columns: rowid_default:14 column3:10 column4:11 column12:12 column13:13
+      ├── columns: rowid_default:14 column3:10 column4:11 c_cast:12 qc_cast:13
       ├── cardinality: [2 - 2]
       ├── volatile, has-placeholder
       ├── values
-      │    ├── columns: column12:12 column13:13 column3:10 column4:11
+      │    ├── columns: c_cast:12 qc_cast:13 column3:10 column4:11
       │    ├── cardinality: [2 - 2]
       │    ├── immutable, has-placeholder
       │    ├── ('', 'f', 1, 'bar')
@@ -1116,28 +1116,28 @@ INSERT INTO assn_cast (c, qc, i, s) (SELECT ' ', 'foo', '1', unnest(ARRAY[1, 2,
 insert assn_cast
  ├── columns: <none>
  ├── insert-mapping:
- │    ├── column12:12 => c:1
- │    ├── column13:13 => qc:2
+ │    ├── c_cast:12 => c:1
+ │    ├── qc_cast:13 => qc:2
  │    ├── "?column?":11 => i:3
- │    ├── column14:14 => s:4
+ │    ├── s_cast:14 => s:4
  │    └── rowid_default:15 => rowid:5
  ├── cardinality: [0 - 0]
  ├── volatile, mutations
  └── project
-      ├── columns: rowid_default:15 column12:12!null column13:13!null "?column?":11!null column14:14!null
+      ├── columns: rowid_default:15 c_cast:12!null qc_cast:13!null "?column?":11!null s_cast:14!null
       ├── cardinality: [3 - 3]
       ├── volatile
       ├── fd: ()-->(11-13)
       ├── values
-      │    ├── columns: column14:14!null
+      │    ├── columns: s_cast:14!null
       │    ├── cardinality: [3 - 3]
       │    ├── ('1',)
       │    ├── ('2',)
       │    └── ('3',)
       └── projections
            ├── unique_rowid() [as=rowid_default:15, volatile]
-           ├── '' [as=column12:12]
-           ├── 'f' [as=column13:13]
+           ├── '' [as=c_cast:12]
+           ├── 'f' [as=qc_cast:13]
            └── 1 [as="?column?":11]
 
 # Do not push assignment casts into values when other projections reference the

pkg/sql/opt/optbuilder/mutation_builder.go

@@ -1441,7 +1441,7 @@ func (mb *mutationBuilder) addAssignmentCasts(srcCols opt.OptionalColList) {
 		// two columns with different names but the same ID. To get the correct
 		// column, we perform a lookup with the ID and the name. See #61520.
 		scopeCol := projectionScope.getColumnWithIDAndReferenceName(colID, targetCol.ColName())
-		scopeCol.name = scopeCol.name.WithMetadataName("")
+		scopeCol.name = scopeCol.name.WithMetadataName(fmt.Sprintf("%s_cast", targetCol.ColName()))
 		mb.b.populateSynthesizedColumn(scopeCol, cast)
 
 		// Replace old source column with the new one.

pkg/sql/opt/optbuilder/testdata/fk-on-update-cascade

@@ -752,12 +752,12 @@ root
  │    ├── columns: <none>
  │    ├── fetch columns: p:4
  │    ├── update-mapping:
- │    │    └── column8:8 => p:1
+ │    │    └── p_cast:8 => p:1
  │    ├── input binding: &1
  │    ├── cascades
  │    │    └── child_assn_cast_p_fkey
  │    └── project
- │         ├── columns: column8:8!null p:4!null crdb_internal_mvcc_timestamp:5 tableoid:6
+ │         ├── columns: p_cast:8!null p:4!null crdb_internal_mvcc_timestamp:5 tableoid:6
  │         ├── project
  │         │    ├── columns: p_new:7!null p:4!null crdb_internal_mvcc_timestamp:5 tableoid:6
  │         │    ├── select
@@ -769,17 +769,17 @@ root
  │         │    └── projections
  │         │         └── 1.45 [as=p_new:7]
  │         └── projections
- │              └── assignment-cast: DECIMAL(10,2) [as=column8:8]
+ │              └── assignment-cast: DECIMAL(10,2) [as=p_cast:8]
  │                   └── p_new:7
  └── cascade
       └── update child_assn_cast
            ├── columns: <none>
            ├── fetch columns: c:13 child_assn_cast.p:14
            ├── update-mapping:
-           │    └── column19:19 => child_assn_cast.p:10
+           │    └── p_cast:19 => child_assn_cast.p:10
            ├── input binding: &2
            ├── project
-           │    ├── columns: column19:19!null c:13!null child_assn_cast.p:14!null p_old:17!null p_new:18!null
+           │    ├── columns: p_cast:19!null c:13!null child_assn_cast.p:14!null p_old:17!null p_new:18!null
            │    ├── inner-join (hash)
            │    │    ├── columns: c:13!null child_assn_cast.p:14!null p_old:17!null p_new:18!null
            │    │    ├── scan child_assn_cast
@@ -790,13 +790,13 @@ root
            │    │    │    │    ├── columns: p_old:17!null p_new:18!null
            │    │    │    │    └── mapping:
            │    │    │    │         ├──  parent_assn_cast.p:4 => p_old:17
-           │    │    │    │         └──  column8:8 => p_new:18
+           │    │    │    │         └──  p_cast:8 => p_new:18
            │    │    │    └── filters
            │    │    │         └── p_old:17 IS DISTINCT FROM p_new:18
            │    │    └── filters
            │    │         └── child_assn_cast.p:14 = p_old:17
            │    └── projections
-           │         └── assignment-cast: DECIMAL(10) [as=column19:19]
+           │         └── assignment-cast: DECIMAL(10) [as=p_cast:19]
            │              └── p_new:18
            └── f-k-checks
                 └── f-k-checks-item: child_assn_cast(p) -> parent_assn_cast(p)
@@ -805,7 +805,7 @@ root
                           ├── with-scan &2
                           │    ├── columns: p:20!null
                           │    └── mapping:
-                          │         └──  column19:19 => p:20
+                          │         └──  p_cast:19 => p:20
                           ├── scan parent_assn_cast
                           │    └── columns: parent_assn_cast.p:21!null
                           └── filters
@@ -1326,13 +1326,13 @@ root
            ├── columns: <none>
            ├── fetch columns: t.public.child_diff_type.c:12(int) t.public.child_diff_type.p:13(int2)
            ├── update-mapping:
-           │    └── column18:18 => t.public.child_diff_type.p:9
+           │    └── p_cast:18 => t.public.child_diff_type.p:9
            ├── input binding: &2
            ├── cardinality: [0 - 0]
            ├── volatile, mutations
            ├── stats: [rows=0]
            ├── project
-           │    ├── columns: column18:18(int2!null) t.public.child_diff_type.c:12(int!null) t.public.child_diff_type.p:13(int2!null) p_old:16(int!null) p_new:17(int!null)
+           │    ├── columns: p_cast:18(int2!null) t.public.child_diff_type.c:12(int!null) t.public.child_diff_type.p:13(int2!null) p_old:16(int!null) p_new:17(int!null)
            │    ├── immutable
            │    ├── stats: [rows=3.3, distinct(18)=0.333317413, null(18)=0]
            │    ├── key: (12)
@@ -1376,7 +1376,7 @@ root
            │    │              ├── variable: t.public.child_diff_type.p:13 [type=int2]
            │    │              └── variable: p_old:16 [type=int]
            │    └── projections
-           │         └── assignment-cast: INT2 [as=column18:18, type=int2, outer=(17), immutable]
+           │         └── assignment-cast: INT2 [as=p_cast:18, type=int2, outer=(17), immutable]
            │              └── variable: p_new:17 [type=int]
            └── f-k-checks
                 └── f-k-checks-item: child_diff_type(p) -> parent_diff_type(p)
@@ -1389,7 +1389,7 @@ root
                           ├── with-scan &2
                           │    ├── columns: p:19(int2!null)
                           │    ├── mapping:
-                          │    │    └──  column18:18(int2) => p:19(int2)
+                          │    │    └──  p_cast:18(int2) => p:19(int2)
                           │    ├── stats: [rows=3.3, distinct(19)=0.333317413, null(19)=0]
                           │    ├── fd: ()-->(19)
                           │    └── cte-uses

pkg/sql/opt/optbuilder/testdata/fk-on-update-set-default

@@ -804,10 +804,10 @@ root
            ├── columns: <none>
            ├── fetch columns: c:12 child_assn_cast.p:13
            ├── update-mapping:
-           │    └── column19:19 => child_assn_cast.p:9
+           │    └── p_cast:19 => child_assn_cast.p:9
            ├── input binding: &2
            ├── project
-           │    ├── columns: column19:19!null c:12!null child_assn_cast.p:13!null p_old:16!null p_new:17!null
+           │    ├── columns: p_cast:19!null c:12!null child_assn_cast.p:13!null p_old:16!null p_new:17!null
            │    ├── project
            │    │    ├── columns: p_new:18!null c:12!null child_assn_cast.p:13!null p_old:16!null p_new:17!null
            │    │    ├── inner-join (cross)
@@ -828,7 +828,7 @@ root
            │    │    └── projections
            │    │         └── 1.45::DECIMAL(10,2) [as=p_new:18]
            │    └── projections
-           │         └── assignment-cast: DECIMAL(10) [as=column19:19]
+           │         └── assignment-cast: DECIMAL(10) [as=p_cast:19]
            │              └── p_new:18
            └── f-k-checks
                 └── f-k-checks-item: child_assn_cast(p) -> parent_assn_cast(p)
@@ -837,7 +837,7 @@ root
                           ├── with-scan &2
                           │    ├── columns: p:20!null
                           │    └── mapping:
-                          │         └──  column19:19 => p:20
+                          │         └──  p_cast:19 => p:20
                           ├── scan parent_assn_cast
                           │    └── columns: parent_assn_cast.p:21!null
                           └── filters