diff --git a/src/backend/catalog/catalog.c b/src/backend/catalog/catalog.c
index 78b566532e..2a6ddf11ff 100644
--- a/src/backend/catalog/catalog.c
+++ b/src/backend/catalog/catalog.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/catalog.c,v 1.43 2001/08/10 18:57:33 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/catalog.c,v 1.44 2001/11/16 23:30:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -77,6 +77,10 @@ GetDatabasePath(Oid tblNode)
  * IsSystemRelationName
  *		True iff name is the name of a system catalog relation.
  *
+ *		NB: TOAST relations are considered system relations by this test.
+ *		This is appropriate in many places but not all.  Where it's not,
+ *		also check IsToastRelationName.
+ *
  *		We now make a new requirement where system catalog relns must begin
  *		with pg_ while user relns are forbidden to do so.  Make the test
  *		trivial and instantaneous.
@@ -86,12 +90,20 @@ GetDatabasePath(Oid tblNode)
 bool
 IsSystemRelationName(const char *relname)
 {
-	if (relname[0] && relname[1] && relname[2])
-		return (relname[0] == 'p' &&
-				relname[1] == 'g' &&
-				relname[2] == '_');
-	else
-		return FALSE;
+	/* ugly coding for speed */
+	return (relname[0] == 'p' &&
+			relname[1] == 'g' &&
+			relname[2] == '_');
+}
+
+/*
+ * IsToastRelationName
+ *		True iff name is the name of a TOAST support relation (or index).
+ */
+bool
+IsToastRelationName(const char *relname)
+{
+	return strncmp(relname, "pg_toast_", 9) == 0;
 }
 
 /*
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 11f4dc52bf..a868c6c1c0 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/acl.c,v 1.65 2001/10/25 05:49:43 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/acl.c,v 1.66 2001/11/16 23:30:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -385,7 +385,9 @@ acldefault(const char *relname, AclId ownerid)
 	aip = ACL_DAT(acl);
 	aip[0].ai_idtype = ACL_IDTYPE_WORLD;
 	aip[0].ai_id = ACL_ID_WORLD;
-	aip[0].ai_mode = IsSystemRelationName(relname) ? ACL_SELECT : ACL_WORLD_DEFAULT;
+	aip[0].ai_mode = (IsSystemRelationName(relname) &&
+					  !IsToastRelationName(relname)) ? ACL_SELECT
+		: ACL_WORLD_DEFAULT;
 	aip[1].ai_idtype = ACL_IDTYPE_UID;
 	aip[1].ai_id = ownerid;
 	aip[1].ai_mode = ACL_OWNER_DEFAULT;
diff --git a/src/backend/utils/cache/inval.c b/src/backend/utils/cache/inval.c
index 9ebf5f3bf2..40d79942d5 100644
--- a/src/backend/utils/cache/inval.c
+++ b/src/backend/utils/cache/inval.c
@@ -56,7 +56,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/cache/inval.c,v 1.46 2001/10/25 05:49:46 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/cache/inval.c,v 1.47 2001/11/16 23:30:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -437,9 +437,13 @@ PrepareForTupleInvalidation(Relation relation, HeapTuple tuple,
 	 * We only need to worry about invalidation for tuples that are in
 	 * system relations; user-relation tuples are never in catcaches and
 	 * can't affect the relcache either.
+	 *
+	 * TOAST tuples can likewise be ignored here.
 	 */
 	if (!IsSystemRelationName(NameStr(RelationGetForm(relation)->relname)))
 		return;
+	if (IsToastRelationName(NameStr(RelationGetForm(relation)->relname)))
+		return;
 
 	/*
 	 * First let the catcache do its thing
diff --git a/src/include/catalog/catalog.h b/src/include/catalog/catalog.h
index cf4f36fe4e..25f6fcb0c5 100644
--- a/src/include/catalog/catalog.h
+++ b/src/include/catalog/catalog.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: catalog.h,v 1.20 2001/11/05 17:46:31 momjian Exp $
+ * $Id: catalog.h,v 1.21 2001/11/16 23:30:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,6 +22,7 @@ extern char *relpath(RelFileNode rnode);
 extern char *GetDatabasePath(Oid tblNode);
 
 extern bool IsSystemRelationName(const char *relname);
+extern bool IsToastRelationName(const char *relname);
 extern bool IsSharedSystemRelationName(const char *relname);
 
 extern Oid	newoid(void);