sql: add index on pg_namespace(oid)

This will allow us to efficiently join to this table.

Release note: None

pkg/bench/rttanalysis/testdata/benchmark_expectations

@@ -73,8 +73,8 @@ exp,benchmark
 3,ORMQueries/information_schema._pg_index_position
 2,ORMQueries/pg_attribute
 2,ORMQueries/pg_class
-10,ORMQueries/pg_is_other_temp_schema
-18,ORMQueries/pg_is_other_temp_schema_multiple_times
+8,ORMQueries/pg_is_other_temp_schema
+8,ORMQueries/pg_is_other_temp_schema_multiple_times
 4,ORMQueries/pg_my_temp_schema
 4,ORMQueries/pg_my_temp_schema_multiple_times
 4,ORMQueries/pg_namespace

pkg/sql/logictest/testdata/logic_test/create_statements

@@ -4772,12 +4772,14 @@ CREATE TABLE pg_catalog.pg_namespace (
    oid OID NULL,
    nspname NAME NOT NULL,
    nspowner OID NULL,
-   nspacl STRING[] NULL
+   nspacl STRING[] NULL,
+   INDEX pg_namespace_oid_idx (oid ASC) STORING (nspname, nspowner, nspacl)
 )  CREATE TABLE pg_catalog.pg_namespace (
    oid OID NULL,
    nspname NAME NOT NULL,
    nspowner OID NULL,
-   nspacl STRING[] NULL
+   nspacl STRING[] NULL,
+   INDEX pg_namespace_oid_idx (oid ASC) STORING (nspname, nspowner, nspacl)
 )  {}  {}
 CREATE TABLE pg_catalog.pg_opclass (
    oid OID NULL,

pkg/sql/logictest/testdata/logic_test/pg_catalog

@@ -312,7 +312,8 @@ pg_catalog.pg_namespace  CREATE TABLE pg_catalog.pg_namespace (
                          oid OID NULL,
                          nspname NAME NOT NULL,
                          nspowner OID NULL,
-                         nspacl STRING[] NULL
+                         nspacl STRING[] NULL,
+                         INDEX pg_namespace_oid_idx (oid ASC) STORING (nspname, nspowner, nspacl)
 )
 
 query TTBTTTB colnames
@@ -3991,7 +3992,7 @@ objoid      classoid    objsubid  description
 4294967098  4294967123  0         pg_largeobject_metadata was created for compatibility and is currently unimplemented
 4294967096  4294967123  0         locks held by active processes (empty - feature does not exist)
 4294967095  4294967123  0         available materialized views (empty - feature does not exist)
-4294967094  4294967123  0         available namespaces (incomplete; namespaces and databases are congruent in CockroachDB)
+4294967094  4294967123  0         available namespaces
 4294967093  4294967123  0         opclass (empty - Operator classes not supported yet)
 4294967092  4294967123  0         operators (incomplete)
 4294967091  4294967123  0         pg_opfamily was created for compatibility and is currently unimplemented

pkg/sql/pg_catalog.go

@@ -28,6 +28,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/catpb"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/catprivilege"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
+	"github.com/cockroachdb/cockroach/pkg/sql/catalog/schemadesc"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/schemaexpr"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/tabledesc"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/typedesc"
@@ -2091,7 +2092,7 @@ https://www.postgresql.org/docs/9.6/view-pg-matviews.html`,
 }
 
 var pgCatalogNamespaceTable = virtualSchemaTable{
-	comment: `available namespaces (incomplete; namespaces and databases are congruent in CockroachDB)
+	comment: `available namespaces
 https://www.postgresql.org/docs/9.5/catalog-pg-namespace.html`,
 	schema: vtable.PGCatalogNamespace,
 	populate: func(ctx context.Context, p *planner, dbContext catalog.DatabaseDescriptor, addRow func(...tree.Datum) error) error {
@@ -2108,9 +2109,6 @@ https://www.postgresql.org/docs/9.5/catalog-pg-namespace.html`,
 						}
 					} else if sc.SchemaKind() == catalog.SchemaPublic {
 						// admin is the owner of the public schema.
-						//
-						// TODO(ajwerner): The public schema effectively carries the privileges
-						// of the database so consider using the database's owner for public.
 						ownerOID = h.UserOid(username.MakeSQLUsernameFromPreNormalizedString("admin"))
 					}
 					return addRow(
@@ -2122,6 +2120,59 @@ https://www.postgresql.org/docs/9.5/catalog-pg-namespace.html`,
 				})
 			})
 	},
+	indexes: []virtualIndex{
+		{
+			// partial is true because this index does not contain temporary schemas.
+			partial: true,
+			populate: func(ctx context.Context, unwrappedConstraint tree.Datum, p *planner, db catalog.DatabaseDescriptor,
+				addRow func(...tree.Datum) error,
+			) (bool, error) {
+				h := makeOidHasher()
+				coid := tree.MustBeDOid(unwrappedConstraint)
+				ooid := coid.Oid
+				sc, err := func() (catalog.SchemaDescriptor, error) {
+					// The system database still does not have a physical public schema.
+					if !db.HasPublicSchemaWithDescriptor() && ooid == keys.SystemPublicSchemaID {
+						return schemadesc.GetPublicSchema(), nil
+					}
+					if sc, ok := schemadesc.GetVirtualSchemaByID(descpb.ID(ooid)); ok {
+						return sc, nil
+					}
+					return p.Descriptors().GetImmutableSchemaByID(
+						ctx, p.Txn(), descpb.ID(ooid), tree.SchemaLookupFlags{Required: true},
+					)
+				}()
+				if err != nil {
+					if sqlerrors.IsUndefinedSchemaError(err) {
+						// No schema found, so no rows.
+						//nolint:returnerrcheck
+						return false, nil
+					}
+					return false, err
+				}
+				ownerOID := tree.DNull
+				if sc.SchemaKind() == catalog.SchemaUserDefined {
+					var err error
+					ownerOID, err = getOwnerOID(ctx, p, sc)
+					if err != nil {
+						return false, err
+					}
+				} else if sc.SchemaKind() == catalog.SchemaPublic {
+					// admin is the owner of the public schema.
+					ownerOID = h.UserOid(username.MakeSQLUsernameFromPreNormalizedString("admin"))
+				}
+				if err := addRow(
+					schemaOid(sc.GetID()),         // oid
+					tree.NewDString(sc.GetName()), // nspname
+					ownerOID,                      // nspowner
+					tree.DNull,                    // nspacl
+				); err != nil {
+					return false, err
+				}
+				return true, nil
+			},
+		},
+	},
 }
 
 var (

pkg/sql/vtable/pg_catalog.go

@@ -508,7 +508,8 @@ CREATE TABLE pg_catalog.pg_namespace (
 	oid OID,
 	nspname NAME NOT NULL,
 	nspowner OID,
-	nspacl STRING[]
+	nspacl STRING[],
+	INDEX (oid)
 )`
 
 // PGCatalogOpclass describes the schema of the pg_catalog.pg_opclass table.