Arrange to put TOAST tables belonging to temporary tables into special schemas

named pg_toast_temp_nnn, alongside the pg_temp_nnn schemas used for the temp
tables themselves.  This allows low-level code such as the relcache to
recognize that these tables are indeed temporary, which enables various
optimizations such as not WAL-logging changes and using local rather than
shared buffers for access.  Aside from obvious performance benefits, this
provides a solution to bug #3483, in which other backends unexpectedly held
open file references to temporary tables.  The scheme preserves the property
that TOAST tables are not in any schema that's normally in the search path,
so they don't conflict with user table names.

initdb forced because of changes in system view definitions.

contrib/oid2name/oid2name.c

@@ -4,7 +4,7 @@
  *
  * Originally by
  * B. Palmer, bpalmer@crimelabs.net 1-17-2001
- * $PostgreSQL: pgsql/contrib/oid2name/oid2name.c,v 1.31 2007/07/15 22:54:20 tgl Exp $
+ * $PostgreSQL: pgsql/contrib/oid2name/oid2name.c,v 1.32 2007/07/25 22:16:17 tgl Exp $
  */
 #include "postgres_fe.h"
 
@@ -411,7 +411,7 @@ sql_exec_dumpalltables(PGconn *conn, struct options * opts)
 		   "	LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace "
 	"	LEFT JOIN pg_catalog.pg_database d ON d.datname = current_database(),"
 			 "	pg_catalog.pg_tablespace t "
-			 "WHERE relkind IN ('r'%s) AND "
+			 "WHERE relkind IN ('r'%s%s) AND "
 			 "	%s"
 			 "		t.oid = CASE"
 			 "			WHEN reltablespace <> 0 THEN reltablespace"
@@ -419,8 +419,9 @@ sql_exec_dumpalltables(PGconn *conn, struct options * opts)
 			 "		END "
 			 "ORDER BY relname",
 			 opts->extended ? addfields : "",
-			 opts->indexes ? ", 'i', 'S', 't'" : "",
-			 opts->systables ? "" : "n.nspname NOT IN ('pg_catalog', 'pg_toast', 'information_schema') AND");
+			 opts->indexes ? ", 'i', 'S'" : "",
+			 opts->systables ? ", 't'" : "",
+			 opts->systables ? "" : "n.nspname NOT IN ('pg_catalog', 'information_schema') AND n.nspname !~ '^pg_toast' AND");
 
 	sql_exec(conn, todo, opts->quiet);
 }

src/backend/catalog/catalog.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/catalog.c,v 1.70 2007/03/25 19:45:14 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/catalog.c,v 1.71 2007/07/25 22:16:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -24,6 +24,7 @@
 #include "access/transam.h"
 #include "catalog/catalog.h"
 #include "catalog/indexing.h"
+#include "catalog/namespace.h"
 #include "catalog/pg_auth_members.h"
 #include "catalog/pg_authid.h"
 #include "catalog/pg_database.h"
@@ -196,15 +197,17 @@ IsSystemNamespace(Oid namespaceId)
 
 /*
  * IsToastNamespace
- *		True iff namespace is pg_toast.
+ *		True iff namespace is pg_toast or my temporary-toast-table namespace.
  *
- * NOTE: the reason this isn't a macro is to avoid having to include
- * catalog/pg_namespace.h in a lot of places.
+ * Note: this will return false for temporary-toast-table namespaces belonging
+ * to other backends.  Those are treated the same as other backends' regular
+ * temp table namespaces, and access is prevented where appropriate.
  */
 bool
 IsToastNamespace(Oid namespaceId)
 {
-	return namespaceId == PG_TOAST_NAMESPACE;
+	return (namespaceId == PG_TOAST_NAMESPACE) ||
+		isTempToastNamespace(namespaceId);
 }
 
 

src/backend/catalog/namespace.c

@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/namespace.c,v 1.96 2007/04/20 02:37:37 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/namespace.c,v 1.97 2007/07/25 22:16:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -152,6 +152,9 @@ static List *overrideStack = NIL;
  * in a particular backend session (this happens when a CREATE TEMP TABLE
  * command is first executed).	Thereafter it's the OID of the temp namespace.
  *
+ * myTempToastNamespace is the OID of the namespace for my temp tables' toast
+ * tables.  It is set when myTempNamespace is, and is InvalidOid before that.
+ *
  * myTempNamespaceSubID shows whether we've created the TEMP namespace in the
  * current subtransaction.	The flag propagates up the subtransaction tree,
  * so the main transaction will correctly recognize the flag if all
@@ -161,6 +164,8 @@ static List *overrideStack = NIL;
  */
 static Oid	myTempNamespace = InvalidOid;
 
+static Oid	myTempToastNamespace = InvalidOid;
+
 static SubTransactionId myTempNamespaceSubID = InvalidSubTransactionId;
 
 /*
@@ -1599,9 +1604,35 @@ isTempNamespace(Oid namespaceId)
 	return false;
 }
 
+/*
+ * isTempToastNamespace - is the given namespace my temporary-toast-table
+ *		namespace?
+ */
+bool
+isTempToastNamespace(Oid namespaceId)
+{
+	if (OidIsValid(myTempToastNamespace) && myTempToastNamespace == namespaceId)
+		return true;
+	return false;
+}
+
+/*
+ * isTempOrToastNamespace - is the given namespace my temporary-table
+ *		namespace or my temporary-toast-table namespace?
+ */
+bool
+isTempOrToastNamespace(Oid namespaceId)
+{
+	if (OidIsValid(myTempNamespace) &&
+		(myTempNamespace == namespaceId || myTempToastNamespace == namespaceId))
+		return true;
+	return false;
+}
+
 /*
  * isAnyTempNamespace - is the given namespace a temporary-table namespace
- * (either my own, or another backend's)?
+ * (either my own, or another backend's)?  Temporary-toast-table namespaces
+ * are included, too.
  */
 bool
 isAnyTempNamespace(Oid namespaceId)
@@ -1609,29 +1640,42 @@ isAnyTempNamespace(Oid namespaceId)
 	bool		result;
 	char	   *nspname;
 
-	/* If the namespace name starts with "pg_temp_", say "true" */
+	/* True if the namespace name starts with "pg_temp_" or "pg_toast_temp_" */
 	nspname = get_namespace_name(namespaceId);
 	if (!nspname)
 		return false;			/* no such namespace? */
-	result = (strncmp(nspname, "pg_temp_", 8) == 0);
+	result = (strncmp(nspname, "pg_temp_", 8) == 0) ||
+		(strncmp(nspname, "pg_toast_temp_", 14) == 0);
 	pfree(nspname);
 	return result;
 }
 
 /*
  * isOtherTempNamespace - is the given namespace some other backend's
- * temporary-table namespace?
+ * temporary-table namespace (including temporary-toast-table namespaces)?
  */
 bool
 isOtherTempNamespace(Oid namespaceId)
 {
 	/* If it's my own temp namespace, say "false" */
-	if (isTempNamespace(namespaceId))
+	if (isTempOrToastNamespace(namespaceId))
 		return false;
-	/* Else, if the namespace name starts with "pg_temp_", say "true" */
+	/* Else, if it's any temp namespace, say "true" */
 	return isAnyTempNamespace(namespaceId);
 }
 
+/*
+ * GetTempToastNamespace - get the OID of my temporary-toast-table namespace,
+ * which must already be assigned.  (This is only used when creating a toast
+ * table for a temp table, so we must have already done InitTempTableNamespace)
+ */
+Oid
+GetTempToastNamespace(void)
+{
+	Assert(OidIsValid(myTempToastNamespace));
+	return myTempToastNamespace;
+}
+
 
 /*
  * GetOverrideSearchPath - fetch current search path definition in form
@@ -2006,6 +2050,7 @@ InitTempTableNamespace(void)
 {
 	char		namespaceName[NAMEDATALEN];
 	Oid			namespaceId;
+	Oid			toastspaceId;
 
 	Assert(!OidIsValid(myTempNamespace));
 
@@ -2054,12 +2099,31 @@ InitTempTableNamespace(void)
 		RemoveTempRelations(namespaceId);
 	}
 
+	/*
+	 * If the corresponding temp-table namespace doesn't exist yet, create it.
+	 * (We assume there is no need to clean it out if it does exist, since
+	 * dropping a parent table should make its toast table go away.)
+	 */
+	snprintf(namespaceName, sizeof(namespaceName), "pg_toast_temp_%d",
+			 MyBackendId);
+
+	toastspaceId = GetSysCacheOid(NAMESPACENAME,
+								  CStringGetDatum(namespaceName),
+								  0, 0, 0);
+	if (!OidIsValid(toastspaceId))
+	{
+		toastspaceId = NamespaceCreate(namespaceName, BOOTSTRAP_SUPERUSERID);
+		/* Advance command counter to make namespace visible */
+		CommandCounterIncrement();
+	}
+
 	/*
 	 * Okay, we've prepared the temp namespace ... but it's not committed yet,
 	 * so all our work could be undone by transaction rollback.  Set flag for
 	 * AtEOXact_Namespace to know what to do.
 	 */
 	myTempNamespace = namespaceId;
+	myTempToastNamespace = toastspaceId;
 
 	/* It should not be done already. */
 	AssertState(myTempNamespaceSubID == InvalidSubTransactionId);
@@ -2089,6 +2153,7 @@ AtEOXact_Namespace(bool isCommit)
 		else
 		{
 			myTempNamespace = InvalidOid;
+			myTempToastNamespace = InvalidOid;
 			baseSearchPathValid = false;	/* need to rebuild list */
 		}
 		myTempNamespaceSubID = InvalidSubTransactionId;
@@ -2140,6 +2205,7 @@ AtEOSubXact_Namespace(bool isCommit, SubTransactionId mySubid,
 			myTempNamespaceSubID = InvalidSubTransactionId;
 			/* TEMP namespace creation failed, so reset state */
 			myTempNamespace = InvalidOid;
+			myTempToastNamespace = InvalidOid;
 			baseSearchPathValid = false;	/* need to rebuild list */
 		}
 	}

src/backend/catalog/system_views.sql

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 1996-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.38 2007/06/28 00:02:37 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.39 2007/07/25 22:16:18 tgl Exp $
  */
 
 CREATE VIEW pg_roles AS 
@@ -221,11 +221,13 @@ CREATE VIEW pg_stat_all_tables AS
 
 CREATE VIEW pg_stat_sys_tables AS 
     SELECT * FROM pg_stat_all_tables 
-    WHERE schemaname IN ('pg_catalog', 'pg_toast', 'information_schema');
+    WHERE schemaname IN ('pg_catalog', 'information_schema') OR
+          schemaname ~ '^pg_toast';
 
 CREATE VIEW pg_stat_user_tables AS 
     SELECT * FROM pg_stat_all_tables 
-    WHERE schemaname NOT IN ('pg_catalog', 'pg_toast', 'information_schema');
+    WHERE schemaname NOT IN ('pg_catalog', 'information_schema') AND
+          schemaname !~ '^pg_toast';
 
 CREATE VIEW pg_statio_all_tables AS 
     SELECT 
@@ -254,11 +256,13 @@ CREATE VIEW pg_statio_all_tables AS
 
 CREATE VIEW pg_statio_sys_tables AS 
     SELECT * FROM pg_statio_all_tables 
-    WHERE schemaname IN ('pg_catalog', 'pg_toast', 'information_schema');
+    WHERE schemaname IN ('pg_catalog', 'information_schema') OR
+          schemaname ~ '^pg_toast';
 
 CREATE VIEW pg_statio_user_tables AS 
     SELECT * FROM pg_statio_all_tables 
-    WHERE schemaname NOT IN ('pg_catalog', 'pg_toast', 'information_schema');
+    WHERE schemaname NOT IN ('pg_catalog', 'information_schema') AND
+          schemaname !~ '^pg_toast';
 
 CREATE VIEW pg_stat_all_indexes AS 
     SELECT 
@@ -278,11 +282,13 @@ CREATE VIEW pg_stat_all_indexes AS
 
 CREATE VIEW pg_stat_sys_indexes AS 
     SELECT * FROM pg_stat_all_indexes 
-    WHERE schemaname IN ('pg_catalog', 'pg_toast', 'information_schema');
+    WHERE schemaname IN ('pg_catalog', 'information_schema') OR
+          schemaname ~ '^pg_toast';
 
 CREATE VIEW pg_stat_user_indexes AS 
     SELECT * FROM pg_stat_all_indexes 
-    WHERE schemaname NOT IN ('pg_catalog', 'pg_toast', 'information_schema');
+    WHERE schemaname NOT IN ('pg_catalog', 'information_schema') AND
+          schemaname !~ '^pg_toast';
 
 CREATE VIEW pg_statio_all_indexes AS 
     SELECT 
@@ -302,11 +308,13 @@ CREATE VIEW pg_statio_all_indexes AS
 
 CREATE VIEW pg_statio_sys_indexes AS 
     SELECT * FROM pg_statio_all_indexes 
-    WHERE schemaname IN ('pg_catalog', 'pg_toast', 'information_schema');
+    WHERE schemaname IN ('pg_catalog', 'information_schema') OR
+          schemaname ~ '^pg_toast';
 
 CREATE VIEW pg_statio_user_indexes AS 
     SELECT * FROM pg_statio_all_indexes 
-    WHERE schemaname NOT IN ('pg_catalog', 'pg_toast', 'information_schema');
+    WHERE schemaname NOT IN ('pg_catalog', 'information_schema') AND
+          schemaname !~ '^pg_toast';
 
 CREATE VIEW pg_statio_all_sequences AS 
     SELECT 
@@ -322,11 +330,13 @@ CREATE VIEW pg_statio_all_sequences AS
 
 CREATE VIEW pg_statio_sys_sequences AS 
     SELECT * FROM pg_statio_all_sequences 
-    WHERE schemaname IN ('pg_catalog', 'pg_toast', 'information_schema');
+    WHERE schemaname IN ('pg_catalog', 'information_schema') OR
+          schemaname ~ '^pg_toast';
 
 CREATE VIEW pg_statio_user_sequences AS 
     SELECT * FROM pg_statio_all_sequences 
-    WHERE schemaname NOT IN ('pg_catalog', 'pg_toast', 'information_schema');
+    WHERE schemaname NOT IN ('pg_catalog', 'information_schema') AND
+          schemaname !~ '^pg_toast';
 
 CREATE VIEW pg_stat_activity AS 
     SELECT 

src/backend/catalog/toasting.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/toasting.c,v 1.6 2007/04/06 04:21:42 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/toasting.c,v 1.7 2007/07/25 22:16:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,6 +21,7 @@
 #include "catalog/heap.h"
 #include "catalog/index.h"
 #include "catalog/indexing.h"
+#include "catalog/namespace.h"
 #include "catalog/pg_namespace.h"
 #include "catalog/pg_opclass.h"
 #include "catalog/pg_type.h"
@@ -108,6 +109,7 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid)
 	Relation	class_rel;
 	Oid			toast_relid;
 	Oid			toast_idxid;
+	Oid			namespaceid;
 	char		toast_relname[NAMEDATALEN];
 	char		toast_idxname[NAMEDATALEN];
 	IndexInfo  *indexInfo;
@@ -173,16 +175,20 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid)
 	tupdesc->attrs[2]->attstorage = 'p';
 
 	/*
-	 * Note: the toast relation is placed in the regular pg_toast namespace
-	 * even if its master relation is a temp table.  There cannot be any
-	 * naming collision, and the toast rel will be destroyed when its master
-	 * is, so there's no need to handle the toast rel as temp.
-	 *
+	 * Toast tables for regular relations go in pg_toast; those for temp
+	 * relations go into the per-backend temp-toast-table namespace.
+	 */
+	if (rel->rd_istemp)
+		namespaceid = GetTempToastNamespace();
+	else
+		namespaceid = PG_TOAST_NAMESPACE;
+
+	/*
 	 * XXX would it make sense to apply the master's reloptions to the toast
-	 * table?
+	 * table?  Or maybe some toast-specific reloptions?
 	 */
 	toast_relid = heap_create_with_catalog(toast_relname,
-										   PG_TOAST_NAMESPACE,
+										   namespaceid,
 										   rel->rd_rel->reltablespace,
 										   toastOid,
 										   rel->rd_rel->relowner,

src/backend/storage/lmgr/lmgr.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/lmgr.c,v 1.91 2007/06/19 20:13:21 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/lmgr.c,v 1.92 2007/07/25 22:16:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -619,7 +619,7 @@ LockTagIsTemp(const LOCKTAG *tag)
 			/* field1 is dboid, field2 is reloid for all of these */
 			if ((Oid) tag->locktag_field1 == InvalidOid)
 				return false;	/* shared, so not temp */
-			if (isTempNamespace(get_rel_namespace((Oid) tag->locktag_field2)))
+			if (isTempOrToastNamespace(get_rel_namespace((Oid) tag->locktag_field2)))
 				return true;
 			break;
 		case LOCKTAG_TRANSACTION:

src/backend/utils/cache/relcache.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/cache/relcache.c,v 1.261 2007/05/27 03:50:39 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/cache/relcache.c,v 1.262 2007/07/25 22:16:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -838,7 +838,7 @@ RelationBuildDesc(Oid targetRelId, Relation oldrelation)
 	relation->rd_isnailed = false;
 	relation->rd_createSubid = InvalidSubTransactionId;
 	relation->rd_newRelfilenodeSubid = InvalidSubTransactionId;
-	relation->rd_istemp = isTempNamespace(relation->rd_rel->relnamespace);
+	relation->rd_istemp = isTempOrToastNamespace(relation->rd_rel->relnamespace);
 
 	/*
 	 * initialize the tuple descriptor (relation->rd_att).
@@ -2315,7 +2315,7 @@ RelationBuildLocalRelation(const char *relname,
 	need_eoxact_work = true;
 
 	/* is it a temporary relation? */
-	rel->rd_istemp = isTempNamespace(relnamespace);
+	rel->rd_istemp = isTempOrToastNamespace(relnamespace);
 
 	/*
 	 * create a new tuple descriptor from the one passed in.  We do this

src/bin/psql/describe.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/describe.c,v 1.156 2007/06/28 06:40:16 neilc Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/describe.c,v 1.157 2007/07/25 22:16:18 tgl Exp $
  */
 #include "postgres_fe.h"
 #include "describe.h"
@@ -1688,9 +1688,12 @@ listTables(const char *tabtypes, const char *pattern, bool verbose)
 	 * pg_catalog and pg_toast.  (We don't want to hide temp tables though.)
 	 */
 	if (showSystem)
-		appendPQExpBuffer(&buf, "      AND n.nspname = 'pg_catalog'\n");
+		appendPQExpBuffer(&buf,
+						  "  AND n.nspname = 'pg_catalog'\n");
 	else
-		appendPQExpBuffer(&buf, "      AND n.nspname NOT IN ('pg_catalog', 'pg_toast')\n");
+		appendPQExpBuffer(&buf,
+						  "  AND n.nspname <> 'pg_catalog'\n"
+						  "  AND n.nspname !~ '^pg_toast'\n");
 
 	processSQLNamePattern(pset.db, &buf, pattern, true, false,
 						  "n.nspname", "c.relname", NULL,

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.414 2007/07/06 04:15:59 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.415 2007/07/25 22:16:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200707051
+#define CATALOG_VERSION_NO	200707251
 
 #endif

src/include/catalog/namespace.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/namespace.h,v 1.47 2007/04/12 22:34:45 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/namespace.h,v 1.48 2007/07/25 22:16:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -79,8 +79,11 @@ extern char *NameListToString(List *names);
 extern char *NameListToQuotedString(List *names);
 
 extern bool isTempNamespace(Oid namespaceId);
+extern bool isTempToastNamespace(Oid namespaceId);
+extern bool isTempOrToastNamespace(Oid namespaceId);
 extern bool isAnyTempNamespace(Oid namespaceId);
 extern bool isOtherTempNamespace(Oid namespaceId);
+extern Oid	GetTempToastNamespace(void);
 extern void ResetTempTableNamespace(void);
 
 extern OverrideSearchPath *GetOverrideSearchPath(MemoryContext context);