sql: add the crdb_internal.create_type_statements table

This PR adds the `crdb_internal.create_type_statments` table, which
contains create statements for user defined types. This will be used
when generating create statments for `cockroach dump` in #47765.

This PR additionally refactors and deduplicates some code that iterates
over all user defined type descriptors in other virtual tables.

Release note (sql change): Add the
`crdb_internal.create_type_statements` virtual table. It holds create
statements for user defined types.

pkg/cli/zip_test.go

@@ -69,6 +69,7 @@ table_name NOT IN (
 	'backward_dependencies',
 	'builtin_functions',
 	'create_statements',
+	'create_type_statements',
 	'forward_dependencies',
 	'index_columns',
 	'table_columns',

pkg/sql/crdb_internal.go

@@ -73,6 +73,7 @@ var crdbInternal = virtualSchema{
 		sqlbase.CrdbInternalClusterSessionsTableID:      crdbInternalClusterSessionsTable,
 		sqlbase.CrdbInternalClusterSettingsTableID:      crdbInternalClusterSettingsTable,
 		sqlbase.CrdbInternalCreateStmtsTableID:          crdbInternalCreateStmtsTable,
+		sqlbase.CrdbInternalCreateTypeStmtsTableID:      crdbInternalCreateTypeStmtsTable,
 		sqlbase.CrdbInternalFeatureUsageID:              crdbInternalFeatureUsage,
 		sqlbase.CrdbInternalForwardDependenciesTableID:  crdbInternalForwardDependenciesTable,
 		sqlbase.CrdbInternalGossipNodesTableID:          crdbInternalGossipNodesTable,
@@ -1346,6 +1347,57 @@ CREATE TABLE crdb_internal.builtin_functions (
 	},
 }
 
+var crdbInternalCreateTypeStmtsTable = virtualSchemaTable{
+	comment: "CREATE statements for all user defined types accessible by the current user in current database (KV scan)",
+	schema: `
+CREATE TABLE crdb_internal.create_type_statements (
+	database_id        INT,
+  database_name      STRING,
+  schema_name        STRING,
+  descriptor_id      INT,
+  descriptor_name    STRING,
+  create_statement   STRING,
+	INDEX (descriptor_id)
+)
+`,
+	populate: func(ctx context.Context, p *planner, db *DatabaseDescriptor, addRow func(...tree.Datum) error) error {
+		return forEachTypeDesc(ctx, p, db, func(db *DatabaseDescriptor, sc string, typeDesc *TypeDescriptor) error {
+			switch typeDesc.Kind {
+			case sqlbase.TypeDescriptor_ENUM:
+				var enumLabels []string
+				for i := range typeDesc.EnumMembers {
+					enumLabels = append(enumLabels, typeDesc.EnumMembers[i].LogicalRepresentation)
+				}
+				name, err := tree.NewUnresolvedObjectName(3, [3]string{typeDesc.Name, sc, db.Name}, 0)
+				if err != nil {
+					return err
+				}
+				node := &tree.CreateType{
+					Variety:    tree.Enum,
+					TypeName:   name,
+					EnumLabels: enumLabels,
+				}
+				if err := addRow(
+					tree.NewDInt(tree.DInt(db.ID)),       // database_id
+					tree.NewDString(db.Name),             // database_name
+					tree.NewDString(sc),                  // schema_name
+					tree.NewDInt(tree.DInt(typeDesc.ID)), // descriptor_id
+					tree.NewDString(typeDesc.Name),       // descriptor_name
+					tree.NewDString(tree.AsString(node)), // create_statement
+				); err != nil {
+					return err
+				}
+			case sqlbase.TypeDescriptor_ALIAS:
+			// Alias types are created implicitly, so we don't have create
+			// statements for them.
+			default:
+				return errors.AssertionFailedf("unknown type descriptor kind %s", typeDesc.Kind.String())
+			}
+			return nil
+		})
+	},
+}
+
 // Prepare the row populate function.
 var typeView = tree.NewDString("view")
 var typeTable = tree.NewDString("table")

pkg/sql/information_schema.go

@@ -1530,6 +1530,41 @@ func forEachDatabaseDesc(
 	return nil
 }
 
+// forEachTypeDesc calls a function for each TypeDescriptor. If dbContext is
+// not nil, then the function is called for only TypeDescriptors within the
+// given database.
+func forEachTypeDesc(
+	ctx context.Context,
+	p *planner,
+	dbContext *DatabaseDescriptor,
+	fn func(db *DatabaseDescriptor, sc string, typ *TypeDescriptor) error,
+) error {
+	descs, err := p.Tables().GetAllDescriptors(ctx, p.txn)
+	if err != nil {
+		return err
+	}
+	schemaNames, err := getSchemaNames(ctx, p, dbContext)
+	if err != nil {
+		return err
+	}
+	lCtx := newInternalLookupCtx(descs, dbContext)
+	for _, id := range lCtx.typIDs {
+		typ := lCtx.typDescs[id]
+		dbDesc, parentExists := lCtx.dbDescs[typ.ParentID]
+		if !parentExists {
+			continue
+		}
+		scName, ok := schemaNames[typ.GetParentSchemaID()]
+		if !ok {
+			return errors.AssertionFailedf("schema id %d not found", typ.GetParentSchemaID())
+		}
+		if err := fn(dbDesc, scName, typ); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 // forEachTableDesc retrieves all table descriptors from the current
 // database and all system databases and iterates through them. For
 // each table, the function will call fn with its respective database

pkg/sql/logictest/testdata/logic_test/crdb_internal

@@ -18,6 +18,7 @@ crdb_internal  cluster_sessions           table
 crdb_internal  cluster_settings           table
 crdb_internal  cluster_transactions       table
 crdb_internal  create_statements          table
+crdb_internal  create_type_statements     table
 crdb_internal  feature_usage              table
 crdb_internal  forward_dependencies       table
 crdb_internal  gossip_alerts              table
@@ -618,3 +619,19 @@ query B
 SELECT crdb_internal.is_admin()
 ----
 false
+
+user root
+
+# Test the crdb_internal.create_type_statements table.
+statement ok
+SET experimental_enable_enums=true;
+CREATE TYPE enum1 AS ENUM ('hello', 'hi');
+CREATE TYPE enum2 AS ENUM ()
+
+query ITTITT
+SELECT * FROM crdb_internal.create_type_statements
+----
+52  test  public  61  enum1  CREATE TYPE test.public.enum1 AS ENUM ('hello', 'hi')
+52  test  public  63  enum2  CREATE TYPE test.public.enum2 AS ENUM ()
+
+# Test the virtual index as well.

pkg/sql/logictest/testdata/logic_test/grant_table

@@ -43,6 +43,7 @@ test           crdb_internal       cluster_sessions                   public   S
 test           crdb_internal       cluster_settings                   public   SELECT
 test           crdb_internal       cluster_transactions               public   SELECT
 test           crdb_internal       create_statements                  public   SELECT
+test           crdb_internal       create_type_statements             public   SELECT
 test           crdb_internal       feature_usage                      public   SELECT
 test           crdb_internal       forward_dependencies               public   SELECT
 test           crdb_internal       gossip_alerts                      public   SELECT

pkg/sql/logictest/testdata/logic_test/information_schema

@@ -223,6 +223,7 @@ crdb_internal       cluster_sessions
 crdb_internal       cluster_settings
 crdb_internal       cluster_transactions
 crdb_internal       create_statements
+crdb_internal       create_type_statements
 crdb_internal       feature_usage
 crdb_internal       forward_dependencies
 crdb_internal       gossip_alerts
@@ -370,6 +371,7 @@ cluster_sessions
 cluster_settings
 cluster_transactions
 create_statements
+create_type_statements
 feature_usage
 forward_dependencies
 gossip_alerts
@@ -524,6 +526,7 @@ system         crdb_internal       cluster_sessions                   SYSTEM VIE
 system         crdb_internal       cluster_settings                   SYSTEM VIEW  NO                  1
 system         crdb_internal       cluster_transactions               SYSTEM VIEW  NO                  1
 system         crdb_internal       create_statements                  SYSTEM VIEW  NO                  1
+system         crdb_internal       create_type_statements             SYSTEM VIEW  NO                  1
 system         crdb_internal       feature_usage                      SYSTEM VIEW  NO                  1
 system         crdb_internal       forward_dependencies               SYSTEM VIEW  NO                  1
 system         crdb_internal       gossip_alerts                      SYSTEM VIEW  NO                  1
@@ -1561,6 +1564,7 @@ NULL     public   system         crdb_internal       cluster_sessions
 NULL     public   system         crdb_internal       cluster_settings                   SELECT          NULL          YES
 NULL     public   system         crdb_internal       cluster_transactions               SELECT          NULL          YES
 NULL     public   system         crdb_internal       create_statements                  SELECT          NULL          YES
+NULL     public   system         crdb_internal       create_type_statements             SELECT          NULL          YES
 NULL     public   system         crdb_internal       feature_usage                      SELECT          NULL          YES
 NULL     public   system         crdb_internal       forward_dependencies               SELECT          NULL          YES
 NULL     public   system         crdb_internal       gossip_alerts                      SELECT          NULL          YES
@@ -1913,6 +1917,7 @@ NULL     public   system         crdb_internal       cluster_sessions
 NULL     public   system         crdb_internal       cluster_settings                   SELECT          NULL          YES
 NULL     public   system         crdb_internal       cluster_transactions               SELECT          NULL          YES
 NULL     public   system         crdb_internal       create_statements                  SELECT          NULL          YES
+NULL     public   system         crdb_internal       create_type_statements             SELECT          NULL          YES
 NULL     public   system         crdb_internal       feature_usage                      SELECT          NULL          YES
 NULL     public   system         crdb_internal       forward_dependencies               SELECT          NULL          YES
 NULL     public   system         crdb_internal       gossip_alerts                      SELECT          NULL          YES