Merge #123562

123562: sql: fix error with DROP VALUE and DROP SCHEMA in same txn r=rafiss a=rafiss

fixes #123539
fixes #123488
fixes #121828
fixes #122785

Release note (bug fix): Fixed a bug that would occur when `ALTER TYPE ... DROP VALUE` is followed by `DROP SCHEMA CASCADE ...` in the same transaction. Previously, the `ALTER TYPE` schema change would get queued up to run at commit time, but by that point, the type may have already been removed, so the commit could fail. This is fixed now.

Co-authored-by: Rafi Shamim <rafi@cockroachlabs.com>

pkg/sql/drop_type.go

@@ -292,6 +292,17 @@ func (p *planner) dropTypeImpl(
 		return err
 	}
 
+	// For this type descriptor, delete queued schema change jobs from the job
+	// cache. If the job had already been scheduled, we would also need to mark
+	// these jobs as successful, but that should never happen for types.
+	//
+	// Note that we still wait for jobs removed from the cache to finish running
+	// after the transaction, since they're not removed from the jobsCollection.
+	// Also, changes made here do not affect schema change jobs created in this
+	// transaction with no mutation ID; they remain in the cache, and will be
+	// updated when writing the job record to drop the table.
+	delete(p.ExtendedEvalContext().jobs.uniqueToCreate, typeDesc.ID)
+
 	if err := p.removeBackRefsFromAllTypesInType(ctx, typeDesc); err != nil {
 		return err
 	}

pkg/sql/jobs_collection.go

@@ -38,7 +38,7 @@ type txnJobsCollection struct {
 	// job for a relation in one transaction. These jobs will be created and
 	// queued at commit time.
 	uniqueToCreate map[descpb.ID]*jobs.Record
-	// uniqueToCreate contains job records that are not unique to a descriptor
+	// nonUniqueToCreate contains job records that are not unique to a descriptor
 	// IDs. These jobs will be created and queued at commit time.
 	nonUniqueToCreate []*jobs.Record
 }

pkg/sql/logictest/testdata/logic_test/drop_schema

@@ -6,3 +6,18 @@ CREATE DATABASE test2
 
 statement error pq: cannot drop schema "public"
 DROP SCHEMA test2.public
+
+# Regression test for ALTER TYPE ... DROP VALUE followed by DROP SCHEMA CASCADE.
+# The type schema change should never be executed, since the DROP SCHEMA would
+# have already removed the type.
+statement ok
+CREATE SCHEMA schema_123539;
+
+statement ok
+CREATE TYPE schema_123539.enum_123539 AS ENUM ('s', 't');
+
+statement ok
+BEGIN;
+ALTER TYPE schema_123539.enum_123539 DROP VALUE 's';
+DROP SCHEMA schema_123539 CASCADE;
+COMMIT;