Change SearchSysCache coding conventions so that a reference count is

maintained for each cache entry.  A cache entry will not be freed until
the matching ReleaseSysCache call has been executed.  This eliminates
worries about cache entries getting dropped while still in use.  See
my posting to pg-hackers of even date for more info.

16 files changed, 526 insertions, 512 deletions

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index a83a5b7c3ab..bc1a2b9918f 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.8 2000/10/16 17:08:05 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.9 2000/11/16 22:30:19 tgl Exp $
  *
 
  *-------------------------------------------------------------------------
@@ -58,8 +58,7 @@ static void del_stats(Oid relid, int attcnt, int *attnums);
 void
 analyze_rel(Oid relid, List *anal_cols2, int MESSAGE_LEVEL)
 {
-	HeapTuple	tuple,
-				typetuple;
+	HeapTuple	tuple;
 	Relation	onerel;
 	int32		i;
 	int			attr_cnt,
@@ -81,20 +80,26 @@ analyze_rel(Oid relid, List *anal_cols2, int MESSAGE_LEVEL)
 	 * Race condition -- if the pg_class tuple has gone away since the
 	 * last time we saw it, we don't need to vacuum it.
 	 */
-	tuple = SearchSysCacheTuple(RELOID,
-								ObjectIdGetDatum(relid),
-								0, 0, 0);
+	tuple = SearchSysCache(RELOID,
+						   ObjectIdGetDatum(relid),
+						   0, 0, 0);
+	if (!HeapTupleIsValid(tuple))
+	{
+		CommitTransactionCommand();
+		return;
+	}
 	/*
 	 * We can VACUUM ANALYZE any table except pg_statistic.
 	 * see update_relstats
 	 */
-	if (!HeapTupleIsValid(tuple) ||
-		strcmp(NameStr(((Form_pg_class) GETSTRUCT(tuple))->relname),
-				StatisticRelationName) == 0)
+	if (strcmp(NameStr(((Form_pg_class) GETSTRUCT(tuple))->relname),
+			   StatisticRelationName) == 0)
 	{
+		ReleaseSysCache(tuple);
 		CommitTransactionCommand();
 		return;
 	}
+	ReleaseSysCache(tuple);
 
 	onerel = heap_open(relid, AccessShareLock);
 
@@ -168,6 +173,7 @@ analyze_rel(Oid relid, List *anal_cols2, int MESSAGE_LEVEL)
 		{
 			pgopform = (Form_pg_operator) GETSTRUCT(func_operator);
 			fmgr_info(pgopform->oprcode, &(stats->f_cmpeq));
+			ReleaseSysCache(func_operator);
 		}
 		else
 			stats->f_cmpeq.fn_addr = NULL;
@@ -178,6 +184,7 @@ analyze_rel(Oid relid, List *anal_cols2, int MESSAGE_LEVEL)
 			pgopform = (Form_pg_operator) GETSTRUCT(func_operator);
 			fmgr_info(pgopform->oprcode, &(stats->f_cmplt));
 			stats->op_cmplt = oprid(func_operator);
+			ReleaseSysCache(func_operator);
 		}
 		else
 		{
@@ -190,17 +197,19 @@ analyze_rel(Oid relid, List *anal_cols2, int MESSAGE_LEVEL)
 		{
 			pgopform = (Form_pg_operator) GETSTRUCT(func_operator);
 			fmgr_info(pgopform->oprcode, &(stats->f_cmpgt));
+			ReleaseSysCache(func_operator);
 		}
 		else
 			stats->f_cmpgt.fn_addr = NULL;
 
-		typetuple = SearchSysCacheTuple(TYPEOID,
-							 ObjectIdGetDatum(stats->attr->atttypid),
-										0, 0, 0);
-		if (HeapTupleIsValid(typetuple))
+		tuple = SearchSysCache(TYPEOID,
+							   ObjectIdGetDatum(stats->attr->atttypid),
+							   0, 0, 0);
+		if (HeapTupleIsValid(tuple))
 		{
-			stats->outfunc = ((Form_pg_type) GETSTRUCT(typetuple))->typoutput;
-			stats->typelem = ((Form_pg_type) GETSTRUCT(typetuple))->typelem;
+			stats->outfunc = ((Form_pg_type) GETSTRUCT(tuple))->typoutput;
+			stats->typelem = ((Form_pg_type) GETSTRUCT(tuple))->typelem;
+			ReleaseSysCache(tuple);
 		}
 		else
 		{
diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c
index 6611f134727..77f7776f6d9 100644
--- a/src/backend/commands/async.c
+++ b/src/backend/commands/async.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/async.c,v 1.70 2000/10/03 03:11:13 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/async.c,v 1.71 2000/11/16 22:30:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -193,9 +193,7 @@ void
 Async_Listen(char *relname, int pid)
 {
 	Relation	lRel;
-	TupleDesc	tdesc;
-	HeapTuple	tuple,
-				newtup;
+	HeapTuple	tuple;
 	Datum		values[Natts_pg_listener];
 	char		nulls[Natts_pg_listener];
 	int			i;
@@ -205,13 +203,12 @@ Async_Listen(char *relname, int pid)
 		elog(DEBUG, "Async_Listen: %s", relname);
 
 	lRel = heap_openr(ListenerRelationName, AccessExclusiveLock);
-	tdesc = RelationGetDescr(lRel);
 
 	/* Detect whether we are already listening on this relname */
-	tuple = SearchSysCacheTuple(LISTENREL, Int32GetDatum(pid),
-								PointerGetDatum(relname),
-								0, 0);
-	if (tuple != NULL)
+	if (SearchSysCacheExists(LISTENREL,
+							 Int32GetDatum(pid),
+							 PointerGetDatum(relname),
+							 0, 0))
 	{
 		/* No need to scan the rest of the table */
 		heap_close(lRel, AccessExclusiveLock);
@@ -235,18 +232,18 @@ Async_Listen(char *relname, int pid)
 	values[i++] = (Datum) 0;	/* no notifies pending */
 
 	tupDesc = lRel->rd_att;
-	newtup = heap_formtuple(tupDesc, values, nulls);
-	heap_insert(lRel, newtup);
+	tuple = heap_formtuple(tupDesc, values, nulls);
+	heap_insert(lRel, tuple);
 	if (RelationGetForm(lRel)->relhasindex)
 	{
 		Relation	idescs[Num_pg_listener_indices];
 
 		CatalogOpenIndices(Num_pg_listener_indices, Name_pg_listener_indices, idescs);
-		CatalogIndexInsert(idescs, Num_pg_listener_indices, lRel, newtup);
+		CatalogIndexInsert(idescs, Num_pg_listener_indices, lRel, tuple);
 		CatalogCloseIndices(Num_pg_listener_indices, idescs);
 	}
 
-	heap_freetuple(newtup);
+	heap_freetuple(tuple);
 
 	heap_close(lRel, AccessExclusiveLock);
 
@@ -296,11 +293,15 @@ Async_Unlisten(char *relname, int pid)
 
 	lRel = heap_openr(ListenerRelationName, AccessExclusiveLock);
 	/* Note we assume there can be only one matching tuple. */
-	lTuple = SearchSysCacheTuple(LISTENREL, Int32GetDatum(pid),
-								PointerGetDatum(relname),
-								0, 0);
-	if (lTuple != NULL)
+	lTuple = SearchSysCache(LISTENREL,
+							Int32GetDatum(pid),
+							PointerGetDatum(relname),
+							0, 0);
+	if (HeapTupleIsValid(lTuple))
+	{
 		heap_delete(lRel, &lTuple->t_self, NULL);
+		ReleaseSysCache(lTuple);
+	}
 	heap_close(lRel, AccessExclusiveLock);
 
 	/*
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index c02bafc3227..5c263e4c26c 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -15,7 +15,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.59 2000/11/08 22:09:57 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.60 2000/11/16 22:30:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -84,15 +84,16 @@ cluster(char *oldrelname, char *oldindexname)
 	/*
 	 * Check that index is in fact an index on the given relation
 	 */
-	tuple = SearchSysCacheTuple(INDEXRELID,
-								ObjectIdGetDatum(OIDOldIndex),
-								0, 0, 0);
+	tuple = SearchSysCache(INDEXRELID,
+						   ObjectIdGetDatum(OIDOldIndex),
+						   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "CLUSTER: no pg_index entry for index %u",
 			 OIDOldIndex);
 	if (((Form_pg_index) GETSTRUCT(tuple))->indrelid != OIDOldHeap)
 		elog(ERROR, "CLUSTER: \"%s\" is not an index for table \"%s\"",
 			 saveoldindexname, saveoldrelname);
+	ReleaseSysCache(tuple);
 
 	/* Drop relcache refcnts, but do NOT give up the locks */
 	heap_close(OldHeap, NoLock);
@@ -184,17 +185,17 @@ copy_index(Oid OIDOldIndex, Oid OIDNewHeap, char *NewIndexName)
 	 * To do this I get the info from pg_index, and add a new index with
 	 * a temporary name.
 	 */
-	Old_pg_index_Tuple = SearchSysCacheTupleCopy(INDEXRELID,
-												 ObjectIdGetDatum(OIDOldIndex),
-												 0, 0, 0);
+	Old_pg_index_Tuple = SearchSysCache(INDEXRELID,
+										ObjectIdGetDatum(OIDOldIndex),
+										0, 0, 0);
 	Assert(Old_pg_index_Tuple);
 	Old_pg_index_Form = (Form_pg_index) GETSTRUCT(Old_pg_index_Tuple);
 
 	indexInfo = BuildIndexInfo(Old_pg_index_Tuple);
 
-	Old_pg_index_relation_Tuple = SearchSysCacheTupleCopy(RELOID,
-														  ObjectIdGetDatum(OIDOldIndex),
-														  0, 0, 0);
+	Old_pg_index_relation_Tuple = SearchSysCache(RELOID,
+												 ObjectIdGetDatum(OIDOldIndex),
+												 0, 0, 0);
 	Assert(Old_pg_index_relation_Tuple);
 	Old_pg_index_relation_Form = (Form_pg_class) GETSTRUCT(Old_pg_index_relation_Tuple);
 
@@ -209,6 +210,9 @@ copy_index(Oid OIDOldIndex, Oid OIDNewHeap, char *NewIndexName)
 
 	setRelhasindex(OIDNewHeap, true);
 
+	ReleaseSysCache(Old_pg_index_Tuple);
+	ReleaseSysCache(Old_pg_index_relation_Tuple);
+
 	index_close(OldIndex);
 	heap_close(NewHeap, NoLock);
 }
diff --git a/src/backend/commands/command.c b/src/backend/commands/command.c
index 958469fa4e1..42f05f0761c 100644
--- a/src/backend/commands/command.c
+++ b/src/backend/commands/command.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.111 2000/11/14 01:57:30 inoue Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.112 2000/11/16 22:30:19 tgl Exp $
  *
  * NOTES
  *	  The PerformAddAttribute() code, like most of the relation
@@ -274,13 +274,13 @@ AlterTableAddColumn(const char *relationName,
 				attrdesc;
 	Oid			myrelid;
 	HeapTuple	reltup;
+	HeapTuple	newreltup;
 	HeapTuple	attributeTuple;
 	Form_pg_attribute attribute;
 	FormData_pg_attribute attributeD;
 	int			i;
 	int			minattnum,
 				maxatts;
-	HeapTuple	tup;
 	Relation	idescs[Num_pg_attr_indices];
 	Relation	ridescs[Num_pg_class_indices];
 	bool		hasindex;
@@ -359,9 +359,9 @@ AlterTableAddColumn(const char *relationName,
 
 	rel = heap_openr(RelationRelationName, RowExclusiveLock);
 
-	reltup = SearchSysCacheTupleCopy(RELNAME,
-									 PointerGetDatum(relationName),
-									 0, 0, 0);
+	reltup = SearchSysCache(RELNAME,
+							PointerGetDatum(relationName),
+							0, 0, 0);
 
 	if (!HeapTupleIsValid(reltup))
 		elog(ERROR, "ALTER TABLE: relation \"%s\" not found",
@@ -371,10 +371,8 @@ AlterTableAddColumn(const char *relationName,
 	 * XXX is the following check sufficient?
 	 */
 	if (((Form_pg_class) GETSTRUCT(reltup))->relkind != RELKIND_RELATION)
-	{
 		elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table",
 			 relationName);
-	}
 
 	minattnum = ((Form_pg_class) GETSTRUCT(reltup))->relnatts;
 	maxatts = minattnum + 1;
@@ -407,12 +405,10 @@ AlterTableAddColumn(const char *relationName,
 		char	   *typename;
 		int			attnelems;
 
-		tup = SearchSysCacheTuple(ATTNAME,
-								  ObjectIdGetDatum(reltup->t_data->t_oid),
-								  PointerGetDatum(colDef->colname),
-								  0, 0);
-
-		if (HeapTupleIsValid(tup))
+		if (SearchSysCacheExists(ATTNAME,
+								 ObjectIdGetDatum(reltup->t_data->t_oid),
+								 PointerGetDatum(colDef->colname),
+								 0, 0))
 			elog(ERROR, "ALTER TABLE: column name \"%s\" already exists in table \"%s\"",
 				 colDef->colname, relationName);
 
@@ -430,13 +426,13 @@ AlterTableAddColumn(const char *relationName,
 		else
 			attnelems = 0;
 
-		typeTuple = SearchSysCacheTuple(TYPENAME,
-										PointerGetDatum(typename),
-										0, 0, 0);
-		tform = (Form_pg_type) GETSTRUCT(typeTuple);
-
+		typeTuple = SearchSysCache(TYPENAME,
+								   PointerGetDatum(typename),
+								   0, 0, 0);
 		if (!HeapTupleIsValid(typeTuple))
 			elog(ERROR, "ALTER TABLE: type \"%s\" does not exist", typename);
+		tform = (Form_pg_type) GETSTRUCT(typeTuple);
+
 		namestrcpy(&(attribute->attname), colDef->colname);
 		attribute->atttypid = typeTuple->t_data->t_oid;
 		attribute->attlen = tform->typlen;
@@ -453,6 +449,8 @@ AlterTableAddColumn(const char *relationName,
 		attribute->atthasdef = (colDef->raw_default != NULL ||
 								colDef->cooked_default != NULL);
 
+		ReleaseSysCache(typeTuple);
+
 		heap_insert(attrdesc, attributeTuple);
 		if (hasindex)
 			CatalogIndexInsert(idescs,
@@ -466,15 +464,21 @@ AlterTableAddColumn(const char *relationName,
 
 	heap_close(attrdesc, RowExclusiveLock);
 
-	((Form_pg_class) GETSTRUCT(reltup))->relnatts = maxatts;
-	heap_update(rel, &reltup->t_self, reltup, NULL);
+	/*
+	 * Update number of attributes in pg_class tuple
+	 */
+	newreltup = heap_copytuple(reltup);
+
+	((Form_pg_class) GETSTRUCT(newreltup))->relnatts = maxatts;
+	heap_update(rel, &newreltup->t_self, newreltup, NULL);
 
 	/* keep catalog indices current */
 	CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, ridescs);
-	CatalogIndexInsert(ridescs, Num_pg_class_indices, rel, reltup);
+	CatalogIndexInsert(ridescs, Num_pg_class_indices, rel, newreltup);
 	CatalogCloseIndices(Num_pg_class_indices, ridescs);
 
-	heap_freetuple(reltup);
+	heap_freetuple(newreltup);
+	ReleaseSysCache(reltup);
 
 	heap_close(rel, NoLock);
 
@@ -555,11 +559,10 @@ AlterTableAlterColumn(const char *relationName,
 	/*
 	 * get the number of the attribute
 	 */
-	tuple = SearchSysCacheTuple(ATTNAME,
-								ObjectIdGetDatum(myrelid),
-								PointerGetDatum(colName),
-								0, 0);
-
+	tuple = SearchSysCache(ATTNAME,
+						   ObjectIdGetDatum(myrelid),
+						   PointerGetDatum(colName),
+						   0, 0);
 	if (!HeapTupleIsValid(tuple))
 	{
 		heap_close(rel, AccessExclusiveLock);
@@ -568,6 +571,7 @@ AlterTableAlterColumn(const char *relationName,
 	}
 
 	attnum = ((Form_pg_attribute) GETSTRUCT(tuple))->attnum;
+	ReleaseSysCache(tuple);
 
 	if (newDefault)				/* SET DEFAULT */
 	{
@@ -595,7 +599,6 @@ AlterTableAlterColumn(const char *relationName,
 		Relation	attr_rel;
 		ScanKeyData scankeys[3];
 		HeapScanDesc scan;
-		HeapTuple	tuple;
 
 		attr_rel = heap_openr(AttributeRelationName, AccessExclusiveLock);
 		ScanKeyEntryInitialize(&scankeys[0], 0x0,
@@ -867,10 +870,11 @@ RemoveColumnReferences(Oid reloid, int attnum, bool checkonly, HeapTuple reltup)
 				}
 				else
 				{
-					htup = SearchSysCacheTuple(RELOID,
-									 ObjectIdGetDatum(index->indexrelid),
-											   0, 0, 0);
+					htup = SearchSysCache(RELOID,
+										  ObjectIdGetDatum(index->indexrelid),
+										  0, 0, 0);
 					RemoveIndex(NameStr(((Form_pg_class) GETSTRUCT(htup))->relname));
+					ReleaseSysCache(htup);
 				}
 				break;
 			}
@@ -941,18 +945,19 @@ AlterTableDropColumn(const char *relationName,
 	if (length(find_all_inheritors(myrelid)) > 1)
 		elog(ERROR, "ALTER TABLE: cannot drop a column on table that is inherited from");
 
-
 	/*
 	 * lock the pg_class tuple for update
 	 */
-	reltup = SearchSysCacheTuple(RELNAME, PointerGetDatum(relationName),
-								 0, 0, 0);
-
+	rel = heap_openr(RelationRelationName, RowExclusiveLock);
+	reltup = SearchSysCache(RELNAME,
+							PointerGetDatum(relationName),
+							0, 0, 0);
 	if (!HeapTupleIsValid(reltup))
 		elog(ERROR, "ALTER TABLE: relation \"%s\" not found",
 			 relationName);
-	rel = heap_openr(RelationRelationName, RowExclusiveLock);
 	classtuple.t_self = reltup->t_self;
+	ReleaseSysCache(reltup);
+
 	switch (heap_mark4update(rel, &classtuple, &buffer))
 	{
 		case HeapTupleSelfUpdated:
@@ -976,19 +981,21 @@ AlterTableDropColumn(const char *relationName,
 	attrdesc = heap_openr(AttributeRelationName, RowExclusiveLock);
 
 	/*
-	 * Get the target pg_attribute tuple
+	 * Get the target pg_attribute tuple and make a modifiable copy
 	 */
-	tup = SearchSysCacheTupleCopy(ATTNAME,
-								  ObjectIdGetDatum(reltup->t_data->t_oid),
-								  PointerGetDatum(colName), 0, 0);
+	tup = SearchSysCacheCopy(ATTNAME,
+							 ObjectIdGetDatum(reltup->t_data->t_oid),
+							 PointerGetDatum(colName),
+							 0, 0);
 	if (!HeapTupleIsValid(tup))
 		elog(ERROR, "ALTER TABLE: column name \"%s\" doesn't exist in table \"%s\"",
 			 colName, relationName);
 
 	attribute = (Form_pg_attribute) GETSTRUCT(tup);
-	if (attribute->attnum <= 0)
-		elog(ERROR, "ALTER TABLE: column name \"%s\" was already dropped", colName);
 	attnum = attribute->attnum;
+	if (attnum <= 0)
+		elog(ERROR, "ALTER TABLE: column name \"%s\" was already dropped",
+			 colName);
 	attoid = tup->t_data->t_oid;
 
 	/*
@@ -1226,10 +1233,9 @@ AlterTableAddConstraint(char *relationName,
 			int			count;
 			List       *indexoidlist,
 				*indexoidscan;
-			Form_pg_index indexStruct = NULL;
 			Form_pg_attribute *rel_attrs = NULL;
-			int                     i;
-			int found=0;
+			int			i;
+			bool		found = false;
 
 			if (get_temp_rel_by_username(fkconstraint->pktable_name)!=NULL &&
 				get_temp_rel_by_username(relationName)==NULL) {
@@ -1264,42 +1270,50 @@ AlterTableAddConstraint(char *relationName,
 			indexoidlist = RelationGetIndexList(pkrel);
 
 			foreach(indexoidscan, indexoidlist)
+			{
+				Oid             indexoid = lfirsti(indexoidscan);
+				HeapTuple       indexTuple;
+				Form_pg_index	indexStruct;
+
+				indexTuple = SearchSysCache(INDEXRELID,
+											ObjectIdGetDatum(indexoid),
+											0, 0, 0);
+				if (!HeapTupleIsValid(indexTuple))
+					elog(ERROR, "transformFkeyGetPrimaryKey: index %u not found",
+						 indexoid);
+				indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
+
+				if (indexStruct->indisunique)
 				{
-					Oid             indexoid = lfirsti(indexoidscan);
-					HeapTuple       indexTuple;
-					List *attrl;
-					indexTuple = SearchSysCacheTuple(INDEXRELID,
-													 ObjectIdGetDatum(indexoid),
-													 0, 0, 0);
-					if (!HeapTupleIsValid(indexTuple))
-						elog(ERROR, "transformFkeyGetPrimaryKey: index %u not found",
-							 indexoid);
-					indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
-
-					if (indexStruct->indisunique) {
-						/* go through the fkconstraint->pk_attrs list */
-						foreach(attrl, fkconstraint->pk_attrs) {
-							Ident *attr=lfirst(attrl);
-							found=0;
-							for (i = 0; i < INDEX_MAX_KEYS && indexStruct->indkey[i] != 0; i++)
+					List	   *attrl;
+
+					/* go through the fkconstraint->pk_attrs list */
+					foreach(attrl, fkconstraint->pk_attrs)
+					{
+						Ident *attr=lfirst(attrl);
+						found = false;
+						for (i = 0; i < INDEX_MAX_KEYS && indexStruct->indkey[i] != 0; i++)
+						{
+							int pkattno = indexStruct->indkey[i];
+							if (pkattno>0)
 							{
-								int pkattno = indexStruct->indkey[i];
-								if (pkattno>0) {
-									char *name = NameStr(rel_attrs[pkattno-1]->attname);
-									if (strcmp(name, attr->name)==0) {
-										found=1;
-										break;
-									}
+								char *name = NameStr(rel_attrs[pkattno-1]->attname);
+								if (strcmp(name, attr->name)==0)
+								{
+									found = true;
+									break;
 								}
 							}
-							if (!found)
-								break;
 						}
+						if (!found)
+							break;
 					}
-					if (found)
-						break;
-					indexStruct = NULL;
 				}
+				ReleaseSysCache(indexTuple);
+				if (found)
+					break;
+			}
+
 			if (!found)
 				elog(ERROR, "UNIQUE constraint matching given keys for referenced table \"%s\" not found",
 					 fkconstraint->pktable_name);
@@ -1309,17 +1323,18 @@ AlterTableAddConstraint(char *relationName,
 
 			rel_attrs = rel->rd_att->attrs;
 			if (fkconstraint->fk_attrs!=NIL) {
-				int found=0;
 				List *fkattrs;
 				Ident *fkattr;
+
+				found = false;
 				foreach(fkattrs, fkconstraint->fk_attrs) {
-					int count=0;
-					found=0;
+					int count;
+					found = false;
 					fkattr=lfirst(fkattrs);
-					for (; count < rel->rd_att->natts; count++) {
+					for (count = 0; count < rel->rd_att->natts; count++) {
 						char *name = NameStr(rel->rd_att->attrs[count]->attname);
 						if (strcmp(name, fkattr->name)==0) {
-							found=1;
+							found = true;
 							break;
 						}
 					}
@@ -1441,20 +1456,22 @@ AlterTableOwner(const char *relationName, const char *newOwnerName)
 	/*
 	 * look up the new owner in pg_shadow and get the sysid
 	 */
-	tuple = SearchSysCacheTuple(SHADOWNAME, PointerGetDatum(newOwnerName),
-								0, 0, 0);
+	tuple = SearchSysCache(SHADOWNAME,
+						   PointerGetDatum(newOwnerName),
+						   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "ALTER TABLE: user \"%s\" not found", newOwnerName);
-
 	newOwnerSysid = ((Form_pg_shadow) GETSTRUCT(tuple))->usesysid;
+	ReleaseSysCache(tuple);
 
 	/*
-	 * find the table's entry in pg_class and lock it for writing
+	 * find the table's entry in pg_class and make a modifiable copy
 	 */
 	class_rel = heap_openr(RelationRelationName, RowExclusiveLock);
 
-	tuple = SearchSysCacheTupleCopy(RELNAME, PointerGetDatum(relationName),
-								 0, 0, 0);
+	tuple = SearchSysCacheCopy(RELNAME,
+							   PointerGetDatum(relationName),
+							   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "ALTER TABLE: relation \"%s\" not found",
 			 relationName);
@@ -1525,13 +1542,15 @@ AlterTableCreateToastTable(const char *relationName, bool silent)
 	 */
 	class_rel = heap_openr(RelationRelationName, RowExclusiveLock);
 
-	reltup = SearchSysCacheTuple(RELNAME, PointerGetDatum(relationName),
-								 0, 0, 0);
+	reltup = SearchSysCache(RELNAME,
+							PointerGetDatum(relationName),
+							0, 0, 0);
 	if (!HeapTupleIsValid(reltup))
 		elog(ERROR, "ALTER TABLE: relation \"%s\" not found",
 			 relationName);
-
 	classtuple.t_self = reltup->t_self;
+	ReleaseSysCache(reltup);
+
 	switch (heap_mark4update(class_rel, &classtuple, &buffer))
 	{
 		case HeapTupleSelfUpdated:
diff --git a/src/backend/commands/comment.c b/src/backend/commands/comment.c
index bff2b897c6e..8ab997831b9 100644
--- a/src/backend/commands/comment.c
+++ b/src/backend/commands/comment.c
@@ -276,7 +276,6 @@ DeleteComments(Oid oid)
 static void
 CommentRelation(int reltype, char *relname, char *comment)
 {
-
 	HeapTuple	reltuple;
 	Oid			oid;
 	char		relkind;
@@ -288,17 +287,20 @@ CommentRelation(int reltype, char *relname, char *comment)
 
 	/*** Now, attempt to find the oid in the cached version of pg_class ***/
 
-	reltuple = SearchSysCacheTuple(RELNAME, PointerGetDatum(relname),
-								   0, 0, 0);
+	reltuple = SearchSysCache(RELNAME,
+							  PointerGetDatum(relname),
+							  0, 0, 0);
 	if (!HeapTupleIsValid(reltuple))
 		elog(ERROR, "relation '%s' does not exist", relname);
 
 	oid = reltuple->t_data->t_oid;
 
-	/*** Next, verify that the relation type matches the intent ***/
-
 	relkind = ((Form_pg_class) GETSTRUCT(reltuple))->relkind;
 
+	ReleaseSysCache(reltuple);
+
+	/*** Next, verify that the relation type matches the intent ***/
+
 	switch (reltype)
 	{
 		case (INDEX):
@@ -322,7 +324,6 @@ CommentRelation(int reltype, char *relname, char *comment)
 	/*** Create the comments using the tuple's oid ***/
 
 	CreateComments(oid, comment);
-
 }
 
 /*------------------------------------------------------------------
@@ -340,9 +341,7 @@ CommentRelation(int reltype, char *relname, char *comment)
 static void
 CommentAttribute(char *relname, char *attrname, char *comment)
 {
-
 	Relation	relation;
-	HeapTuple	attrtuple;
 	Oid			oid;
 
 	/*** First, check object security ***/
@@ -350,15 +349,19 @@ CommentAttribute(char *relname, char *attrname, char *comment)
 	if (!pg_ownercheck(GetUserId(), relname, RELNAME))
 		elog(ERROR, "you are not permitted to comment on class '%s\'", relname);
 
-	/*** Now, fetch the attribute oid from the system cache ***/
+	/* Open the containing relation to ensure it won't go away meanwhile */
 
 	relation = heap_openr(relname, AccessShareLock);
-	attrtuple = SearchSysCacheTuple(ATTNAME, ObjectIdGetDatum(relation->rd_id),
-									PointerGetDatum(attrname), 0, 0);
-	if (!HeapTupleIsValid(attrtuple))
+
+	/*** Now, fetch the attribute oid from the system cache ***/
+
+	oid = GetSysCacheOid(ATTNAME,
+						 ObjectIdGetDatum(relation->rd_id),
+						 PointerGetDatum(attrname),
+						 0, 0);
+	if (!OidIsValid(oid))
 		elog(ERROR, "'%s' is not an attribute of class '%s'",
 			 attrname, relname);
-	oid = attrtuple->t_data->t_oid;
 
 	/*** Call CreateComments() to create/drop the comments ***/
 
@@ -412,11 +415,13 @@ CommentDatabase(char *database, char *comment)
 	/*** Now, fetch user information ***/
 
 	userid = GetUserId();
-	usertuple = SearchSysCacheTuple(SHADOWSYSID, ObjectIdGetDatum(userid),
-									0, 0, 0);
+	usertuple = SearchSysCache(SHADOWSYSID,
+							   ObjectIdGetDatum(userid),
+							   0, 0, 0);
 	if (!HeapTupleIsValid(usertuple))
 		elog(ERROR, "invalid user id %u", (unsigned) userid);
 	superuser = ((Form_pg_shadow) GETSTRUCT(usertuple))->usesuper;
+	ReleaseSysCache(usertuple);
 
 	/*** Allow if the userid matches the database dba or is a superuser ***/
 
@@ -452,8 +457,6 @@ CommentDatabase(char *database, char *comment)
 static void
 CommentRewrite(char *rule, char *comment)
 {
-
-	HeapTuple	rewritetuple;
 	Oid			oid;
 	char	   *relation;
 	int			aclcheck;
@@ -472,17 +475,15 @@ CommentRewrite(char *rule, char *comment)
 
 	/*** Next, find the rule's oid ***/
 
-	rewritetuple = SearchSysCacheTuple(RULENAME, PointerGetDatum(rule),
-									   0, 0, 0);
-	if (!HeapTupleIsValid(rewritetuple))
+	oid = GetSysCacheOid(RULENAME,
+						 PointerGetDatum(rule),
+						 0, 0, 0);
+	if (!OidIsValid(oid))
 		elog(ERROR, "rule '%s' does not exist", rule);
 
-	oid = rewritetuple->t_data->t_oid;
-
 	/*** Call CreateComments() to create/drop the comments ***/
 
 	CreateComments(oid, comment);
-
 }
 
 /*------------------------------------------------------------------
@@ -499,8 +500,6 @@ CommentRewrite(char *rule, char *comment)
 static void
 CommentType(char *type, char *comment)
 {
-
-	HeapTuple	typetuple;
 	Oid			oid;
 
 	/*** First, validate user ***/
@@ -515,17 +514,15 @@ CommentType(char *type, char *comment)
 
 	/*** Next, find the type's oid ***/
 
-	typetuple = SearchSysCacheTuple(TYPENAME, PointerGetDatum(type),
-									0, 0, 0);
-	if (!HeapTupleIsValid(typetuple))
+	oid = GetSysCacheOid(TYPENAME,
+						 PointerGetDatum(type),
+						 0, 0, 0);
+	if (!OidIsValid(oid))
 		elog(ERROR, "type '%s' does not exist", type);
 
-	oid = typetuple->t_data->t_oid;
-
 	/*** Call CreateComments() to create/drop the comments ***/
 
 	CreateComments(oid, comment);
-
 }
 
 /*------------------------------------------------------------------
@@ -543,7 +540,6 @@ CommentAggregate(char *aggregate, List *arguments, char *comment)
 {
 	TypeName   *aggtype = (TypeName *) lfirst(arguments);
 	char	   *aggtypename = NULL;
-	HeapTuple	aggtuple;
 	Oid			baseoid,
 				oid;
 	bool		defined;
@@ -580,9 +576,11 @@ CommentAggregate(char *aggregate, List *arguments, char *comment)
 
 	/*** Now, attempt to find the actual tuple in pg_aggregate ***/
 
-	aggtuple = SearchSysCacheTuple(AGGNAME, PointerGetDatum(aggregate),
-								   ObjectIdGetDatum(baseoid), 0, 0);
-	if (!HeapTupleIsValid(aggtuple))
+	oid = GetSysCacheOid(AGGNAME,
+						 PointerGetDatum(aggregate),
+						 ObjectIdGetDatum(baseoid),
+						 0, 0);
+	if (!OidIsValid(oid))
 	{
 		if (aggtypename)
 		{
@@ -593,12 +591,9 @@ CommentAggregate(char *aggregate, List *arguments, char *comment)
 			elog(ERROR, "aggregate '%s' does not exist", aggregate);
 	}
 
-	oid = aggtuple->t_data->t_oid;
-
 	/*** Call CreateComments() to create/drop the comments ***/
 
 	CreateComments(oid, comment);
-
 }
 
 /*------------------------------------------------------------------
@@ -615,8 +610,6 @@ CommentAggregate(char *aggregate, List *arguments, char *comment)
 static void
 CommentProc(char *function, List *arguments, char *comment)
 {
-	HeapTuple	argtuple,
-				functuple;
 	Oid			oid,
 				argoids[FUNC_MAX_ARGS];
 	int			i,
@@ -640,12 +633,11 @@ CommentProc(char *function, List *arguments, char *comment)
 			argoids[i] = InvalidOid;
 		else
 		{
-			argtuple = SearchSysCacheTuple(TYPENAME,
-										   PointerGetDatum(typnam),
-										   0, 0, 0);
-			if (!HeapTupleIsValid(argtuple))
+			argoids[i] = GetSysCacheOid(TYPENAME,
+										PointerGetDatum(typnam),
+										0, 0, 0);
+			if (!OidIsValid(argoids[i]))
 				elog(ERROR, "CommentProc: type '%s' not found", typnam);
-			argoids[i] = argtuple->t_data->t_oid;
 		}
 	}
 
@@ -659,14 +651,14 @@ CommentProc(char *function, List *arguments, char *comment)
 
 	/*** Now, find the corresponding oid for this procedure ***/
 
-	functuple = SearchSysCacheTuple(PROCNAME, PointerGetDatum(function),
-									Int32GetDatum(argcount),
-									PointerGetDatum(argoids), 0);
-	if (!HeapTupleIsValid(functuple))
+	oid = GetSysCacheOid(PROCNAME,
+						 PointerGetDatum(function),
+						 Int32GetDatum(argcount),
+						 PointerGetDatum(argoids),
+						 0);
+	if (!OidIsValid(oid))
 		func_error("CommentProc", function, argcount, argoids, NULL);
 
-	oid = functuple->t_data->t_oid;
-
 	/*** Call CreateComments() to create/drop the comments ***/
 
 	CreateComments(oid, comment);
@@ -738,10 +730,11 @@ CommentOperator(char *opername, List *arguments, char *comment)
 
 	/*** Attempt to fetch the operator oid ***/
 
-	optuple = SearchSysCacheTupleCopy(OPERNAME, PointerGetDatum(opername),
-									  ObjectIdGetDatum(leftoid),
-									  ObjectIdGetDatum(rightoid),
-									  CharGetDatum(oprtype));
+	optuple = SearchSysCache(OPERNAME,
+							 PointerGetDatum(opername),
+							 ObjectIdGetDatum(leftoid),
+							 ObjectIdGetDatum(rightoid),
+							 CharGetDatum(oprtype));
 	if (!HeapTupleIsValid(optuple))
 		elog(ERROR, "operator '%s' does not exist", opername);
 
@@ -764,6 +757,8 @@ CommentOperator(char *opername, List *arguments, char *comment)
 	if (oid == InvalidOid)
 		elog(ERROR, "operator '%s' does not have an underlying function", opername);
 
+	ReleaseSysCache(optuple);
+
 	/*** Call CreateComments() to create/drop the comments ***/
 
 	CreateComments(oid, comment);
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 2877999500c..bbbb5aa2cfc 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.123 2000/11/12 00:36:56 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.124 2000/11/16 22:30:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -48,9 +48,9 @@
 static void CopyTo(Relation rel, bool binary, bool oids, FILE *fp, char *delim, char *null_print);
 static void CopyFrom(Relation rel, bool binary, bool oids, FILE *fp, char *delim, char *null_print);
 static Oid	GetOutputFunction(Oid type);
-static Oid	GetTypeElement(Oid type);
 static Oid	GetInputFunction(Oid type);
-static Oid	IsTypeByVal(Oid type);
+static Oid	GetTypeElement(Oid type);
+static bool IsTypeByVal(Oid type);
 static void CopyReadNewline(FILE *fp, int *newline);
 static char *CopyReadAttribute(FILE *fp, bool *isnull, char *delim, int *newline, char *null_print);
 
@@ -669,7 +669,7 @@ CopyFrom(Relation rel, bool binary, bool oids, FILE *fp,
 			continue;
 		}
 #endif	 /* _DROP_COLUMN_HACK__ */
-		byval[i] = (bool) IsTypeByVal(attr[i]->atttypid);
+		byval[i] = IsTypeByVal(attr[i]->atttypid);
 	}
 
 	lineno = 0;
@@ -893,65 +893,64 @@ static Oid
 GetOutputFunction(Oid type)
 {
 	HeapTuple	typeTuple;
-
-	typeTuple = SearchSysCacheTuple(TYPEOID,
-									ObjectIdGetDatum(type),
-									0, 0, 0);
-
-	if (HeapTupleIsValid(typeTuple))
-		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typoutput;
-
-	elog(ERROR, "GetOutputFunction: Cache lookup of type %u failed", type);
-	return InvalidOid;
+	Oid			result;
+
+	typeTuple = SearchSysCache(TYPEOID,
+							   ObjectIdGetDatum(type),
+							   0, 0, 0);
+	if (!HeapTupleIsValid(typeTuple))
+		elog(ERROR, "GetOutputFunction: Cache lookup of type %u failed", type);
+	result = ((Form_pg_type) GETSTRUCT(typeTuple))->typoutput;
+	ReleaseSysCache(typeTuple);
+	return result;
 }
 
 static Oid
-GetTypeElement(Oid type)
+GetInputFunction(Oid type)
 {
 	HeapTuple	typeTuple;
-
-	typeTuple = SearchSysCacheTuple(TYPEOID,
-									ObjectIdGetDatum(type),
-									0, 0, 0);
-
-	if (HeapTupleIsValid(typeTuple))
-		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typelem;
-
-	elog(ERROR, "GetOutputFunction: Cache lookup of type %u failed", type);
-	return InvalidOid;
+	Oid			result;
+
+	typeTuple = SearchSysCache(TYPEOID,
+							   ObjectIdGetDatum(type),
+							   0, 0, 0);
+	if (!HeapTupleIsValid(typeTuple))
+		elog(ERROR, "GetInputFunction: Cache lookup of type %u failed", type);
+	result = ((Form_pg_type) GETSTRUCT(typeTuple))->typinput;
+	ReleaseSysCache(typeTuple);
+	return result;
 }
 
 static Oid
-GetInputFunction(Oid type)
+GetTypeElement(Oid type)
 {
 	HeapTuple	typeTuple;
-
-	typeTuple = SearchSysCacheTuple(TYPEOID,
-									ObjectIdGetDatum(type),
-									0, 0, 0);
-
-	if (HeapTupleIsValid(typeTuple))
-		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typinput;
-
-	elog(ERROR, "GetInputFunction: Cache lookup of type %u failed", type);
-	return InvalidOid;
+	Oid			result;
+
+	typeTuple = SearchSysCache(TYPEOID,
+							   ObjectIdGetDatum(type),
+							   0, 0, 0);
+	if (!HeapTupleIsValid(typeTuple))
+		elog(ERROR, "GetTypeElement: Cache lookup of type %u failed", type);
+	result = ((Form_pg_type) GETSTRUCT(typeTuple))->typelem;
+	ReleaseSysCache(typeTuple);
+	return result;
 }
 
-static Oid
+static bool
 IsTypeByVal(Oid type)
 {
 	HeapTuple	typeTuple;
-
-	typeTuple = SearchSysCacheTuple(TYPEOID,
-									ObjectIdGetDatum(type),
-									0, 0, 0);
-
-	if (HeapTupleIsValid(typeTuple))
-		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typbyval;
-
-	elog(ERROR, "GetInputFunction: Cache lookup of type %u failed", type);
-
-	return InvalidOid;
+	bool		result;
+
+	typeTuple = SearchSysCache(TYPEOID,
+							   ObjectIdGetDatum(type),
+							   0, 0, 0);
+	if (!HeapTupleIsValid(typeTuple))
+		elog(ERROR, "IsTypeByVal: Cache lookup of type %u failed", type);
+	result = ((Form_pg_type) GETSTRUCT(typeTuple))->typbyval;
+	ReleaseSysCache(typeTuple);
+	return result;
 }
 
 
diff --git a/src/backend/commands/creatinh.c b/src/backend/commands/creatinh.c
index a1d45d170a1..970782d6da3 100644
--- a/src/backend/commands/creatinh.c
+++ b/src/backend/commands/creatinh.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/creatinh.c,v 1.66 2000/11/13 09:16:55 inoue Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/creatinh.c,v 1.67 2000/11/16 22:30:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -408,11 +408,14 @@ MergeAttributes(List *schema, List *supers, List **supconstr)
 			 * form name, type and constraints
 			 */
 			attributeName = NameStr(attribute->attname);
-			tuple = SearchSysCacheTuple(TYPEOID,
+			tuple = SearchSysCache(TYPEOID,
 								   ObjectIdGetDatum(attribute->atttypid),
-										0, 0, 0);
-			Assert(HeapTupleIsValid(tuple));
-			attributeType = NameStr(((Form_pg_type) GETSTRUCT(tuple))->typname);
+								   0, 0, 0);
+			if (!HeapTupleIsValid(tuple))
+				elog(ERROR, "CREATE TABLE: cache lookup failed for type %u",
+					 attribute->atttypid);
+			attributeType = pstrdup(NameStr(((Form_pg_type) GETSTRUCT(tuple))->typname));
+			ReleaseSysCache(tuple);
 
 			/*
 			 * check validity
@@ -554,22 +557,25 @@ StoreCatalogInheritance(Oid relationId, List *supers)
 	idList = NIL;
 	foreach(entry, supers)
 	{
+		Oid			entryOid;
 		Datum		datum[Natts_pg_inherits];
 		char		nullarr[Natts_pg_inherits];
 
-		tuple = SearchSysCacheTuple(RELNAME,
+		entryOid = GetSysCacheOid(RELNAME,
 								  PointerGetDatum(strVal(lfirst(entry))),
-									0, 0, 0);
-		AssertArg(HeapTupleIsValid(tuple));
+								  0, 0, 0);
+		if (!OidIsValid(entryOid))
+			elog(ERROR, "StoreCatalogInheritance: cache lookup failed for relation \"%s\"",
+				 strVal(lfirst(entry)));
 
 		/*
 		 * build idList for use below
 		 */
-		idList = lappendi(idList, tuple->t_data->t_oid);
+		idList = lappendi(idList, entryOid);
 
-		datum[0] = ObjectIdGetDatum(relationId);		/* inhrel */
-		datum[1] = ObjectIdGetDatum(tuple->t_data->t_oid);		/* inhparent */
-		datum[2] = Int16GetDatum(seqNumber);	/* inhseqno */
+		datum[0] = ObjectIdGetDatum(relationId);	/* inhrel */
+		datum[1] = ObjectIdGetDatum(entryOid);		/* inhparent */
+		datum[2] = Int16GetDatum(seqNumber);		/* inhseqno */
 
 		nullarr[0] = ' ';
 		nullarr[1] = ' ';
@@ -624,11 +630,10 @@ StoreCatalogInheritance(Oid relationId, List *supers)
 
 		for (number = 1;; number += 1)
 		{
-			tuple = SearchSysCacheTuple(INHRELID,
-										ObjectIdGetDatum(id),
-										Int16GetDatum(number),
-										0, 0);
-
+			tuple = SearchSysCache(INHRELID,
+								   ObjectIdGetDatum(id),
+								   Int16GetDatum(number),
+								   0, 0);
 			if (!HeapTupleIsValid(tuple))
 				break;
 
@@ -636,6 +641,8 @@ StoreCatalogInheritance(Oid relationId, List *supers)
 									 GETSTRUCT(tuple))->inhparent,
 									NIL);
 
+			ReleaseSysCache(tuple);
+
 			current = lnext(current);
 		}
 		lnext(current) = next;
@@ -746,35 +753,28 @@ checkAttrExists(const char *attributeName, const char *attributeType, List *sche
 static void
 setRelhassubclassInRelation(Oid relationId, bool relhassubclass)
 {
-        Relation        relationRelation;
-        HeapTuple       tuple;
-        Relation        idescs[Num_pg_class_indices];
-
-        /*
-         * Lock a relation given its Oid. Go to the RelationRelation (i.e.
-         * pg_relation), find the appropriate tuple, and add the specified
-         * lock to it.
-         */
-        relationRelation = heap_openr(RelationRelationName, RowExclusiveLock);
-        tuple = SearchSysCacheTupleCopy(RELOID,
-                                    ObjectIdGetDatum(relationId),
-                                    0, 0, 0)
-;
-        Assert(HeapTupleIsValid(tuple));
-
-        ((Form_pg_class) GETSTRUCT(tuple))->relhassubclass = relhassubclass;
-        heap_update(relationRelation, &tuple->t_self, tuple, NULL);
-
-        /* keep the catalog indices up to date */
-        CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, idescs);
-        CatalogIndexInsert(idescs, Num_pg_class_indices, relationRelation, tuple
-);
-        CatalogCloseIndices(Num_pg_class_indices, idescs);
-
-	heap_freetuple(tuple);
-        heap_close(relationRelation, RowExclusiveLock);
-}
+	Relation		relationRelation;
+	HeapTuple       tuple;
+	Relation        idescs[Num_pg_class_indices];
 
+	/*
+	 * Fetch a modifiable copy of the tuple, modify it, update pg_class.
+	 */
+	relationRelation = heap_openr(RelationRelationName, RowExclusiveLock);
+	tuple = SearchSysCacheCopy(RELOID,
+							   ObjectIdGetDatum(relationId),
+							   0, 0, 0);
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "setRelhassubclassInRelation: cache lookup failed for relation %u", relationId);
 
+	((Form_pg_class) GETSTRUCT(tuple))->relhassubclass = relhassubclass;
+	heap_update(relationRelation, &tuple->t_self, tuple, NULL);
 
+	/* keep the catalog indices up to date */
+	CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, idescs);
+	CatalogIndexInsert(idescs, Num_pg_class_indices, relationRelation, tuple);
+	CatalogCloseIndices(Num_pg_class_indices, idescs);
 
+	heap_freetuple(tuple);
+	heap_close(relationRelation, RowExclusiveLock);
+}
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 70fd952db63..464a9b68fb2 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.67 2000/11/14 18:37:41 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.68 2000/11/16 22:30:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -445,9 +445,9 @@ get_user_info(Oid use_sysid, bool *use_super, bool *use_createdb)
 {
 	HeapTuple	utup;
 
-	utup = SearchSysCacheTuple(SHADOWSYSID,
-							   ObjectIdGetDatum(use_sysid),
-							   0, 0, 0);
+	utup = SearchSysCache(SHADOWSYSID,
+						  ObjectIdGetDatum(use_sysid),
+						  0, 0, 0);
 
 	if (!HeapTupleIsValid(utup))
 		return false;
@@ -457,6 +457,8 @@ get_user_info(Oid use_sysid, bool *use_super, bool *use_createdb)
 	if (use_createdb)
 		*use_createdb = ((Form_pg_shadow) GETSTRUCT(utup))->usecreatedb;
 
+	ReleaseSysCache(utup);
+
 	return true;
 }
 
diff --git a/src/backend/commands/define.c b/src/backend/commands/define.c
index a33d155db9f..9d681a4a50f 100644
--- a/src/backend/commands/define.c
+++ b/src/backend/commands/define.c
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/define.c,v 1.47 2000/10/07 00:58:16 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/define.c,v 1.48 2000/11/16 22:30:18 tgl Exp $
  *
  * DESCRIPTION
  *	  The "DefineFoo" routines take the parse tree and pick out the
@@ -277,10 +277,9 @@ CreateFunction(ProcedureStmt *stmt, CommandDest dest)
 		Form_pg_language languageStruct;
 
 		/* Lookup the language in the system cache */
-		languageTuple = SearchSysCacheTuple(LANGNAME,
-											PointerGetDatum(languageName),
-											0, 0, 0);
-
+		languageTuple = SearchSysCache(LANGNAME,
+									   PointerGetDatum(languageName),
+									   0, 0, 0);
 		if (!HeapTupleIsValid(languageTuple))
 			elog(ERROR,
 				 "Unrecognized language specified in a CREATE FUNCTION: "
@@ -299,12 +298,12 @@ CreateFunction(ProcedureStmt *stmt, CommandDest dest)
 		 * be defined by postgres superusers only
 		 */
 		if (!languageStruct->lanpltrusted && !superuser())
-		{
 			elog(ERROR, "Only users with Postgres superuser privilege "
 				 "are permitted to create a function in the '%s' "
 				 "language.",
 				 languageName);
-		}
+
+		ReleaseSysCache(languageTuple);
 	}
 
 	/*
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index fff6d569753..788701b20fe 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.40 2000/11/08 22:09:57 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.41 2000/11/16 22:30:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -86,7 +86,6 @@ DefineIndex(char *heapRelationName,
 	Oid			relationId;
 	IndexInfo  *indexInfo;
 	int			numberOfAttributes;
-	HeapTuple	tuple;
 	List	   *cnfPred = NIL;
 	bool		lossy = false;
 	List	   *pl;
@@ -111,13 +110,12 @@ DefineIndex(char *heapRelationName,
 	/*
 	 * compute access method id
 	 */
-	tuple = SearchSysCacheTuple(AMNAME,
-								PointerGetDatum(accessMethodName),
-								0, 0, 0);
-	if (!HeapTupleIsValid(tuple))
+	accessMethodId = GetSysCacheOid(AMNAME,
+									PointerGetDatum(accessMethodName),
+									0, 0, 0);
+	if (!OidIsValid(accessMethodId))
 		elog(ERROR, "DefineIndex: access method \"%s\" not found",
 			 accessMethodName);
-	accessMethodId = tuple->t_data->t_oid;
 
 	/*
 	 * XXX Hardwired hacks to check for limitations on supported index types.
@@ -239,21 +237,22 @@ ExtendIndex(char *indexRelationName, Expr *predicate, List *rangetable)
 	/*
 	 * Get index's relation id and access method id from pg_class
 	 */
-	tuple = SearchSysCacheTuple(RELNAME,
-								PointerGetDatum(indexRelationName),
-								0, 0, 0);
+	tuple = SearchSysCache(RELNAME,
+						   PointerGetDatum(indexRelationName),
+						   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "ExtendIndex: index \"%s\" not found",
 			 indexRelationName);
 	indexId = tuple->t_data->t_oid;
 	accessMethodId = ((Form_pg_class) GETSTRUCT(tuple))->relam;
+	ReleaseSysCache(tuple);
 
 	/*
 	 * Extract info from the pg_index tuple for the index
 	 */
-	tuple = SearchSysCacheTuple(INDEXRELID,
-								ObjectIdGetDatum(indexId),
-								0, 0, 0);
+	tuple = SearchSysCache(INDEXRELID,
+						   ObjectIdGetDatum(indexId),
+						   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "ExtendIndex: relation \"%s\" is not an index",
 			 indexRelationName);
@@ -262,6 +261,7 @@ ExtendIndex(char *indexRelationName, Expr *predicate, List *rangetable)
 	relationId = index->indrelid;
 	indexInfo = BuildIndexInfo(tuple);
 	oldPred = indexInfo->ii_Predicate;
+	ReleaseSysCache(tuple);
 
 	if (oldPred == NULL)
 		elog(ERROR, "ExtendIndex: \"%s\" is not a partial index",
@@ -391,16 +391,16 @@ FuncIndexArgs(IndexInfo *indexInfo,
 		HeapTuple	tuple;
 		Form_pg_attribute att;
 
-		tuple = SearchSysCacheTuple(ATTNAME,
-									ObjectIdGetDatum(relId),
-									PointerGetDatum(arg),
-									0, 0);
+		tuple = SearchSysCache(ATTNAME,
+							   ObjectIdGetDatum(relId),
+							   PointerGetDatum(arg),
+							   0, 0);
 		if (!HeapTupleIsValid(tuple))
 			elog(ERROR, "DefineIndex: attribute \"%s\" not found", arg);
 		att = (Form_pg_attribute) GETSTRUCT(tuple);
-
 		indexInfo->ii_KeyAttrNumbers[nargs] = att->attnum;
 		argTypes[nargs] = att->atttypid;
+		ReleaseSysCache(tuple);
 		nargs++;
 	}
 
@@ -465,10 +465,10 @@ NormIndexAttrs(IndexInfo *indexInfo,
 		if (attribute->name == NULL)
 			elog(ERROR, "missing attribute for define index");
 
-		atttuple = SearchSysCacheTupleCopy(ATTNAME,
-										   ObjectIdGetDatum(relId),
-										PointerGetDatum(attribute->name),
-										   0, 0);
+		atttuple = SearchSysCache(ATTNAME,
+								  ObjectIdGetDatum(relId),
+								  PointerGetDatum(attribute->name),
+								  0, 0);
 		if (!HeapTupleIsValid(atttuple))
 			elog(ERROR, "DefineIndex: attribute \"%s\" not found",
 				 attribute->name);
@@ -479,7 +479,7 @@ NormIndexAttrs(IndexInfo *indexInfo,
 		classOidP[attn] = GetAttrOpClass(attribute, attform->atttypid,
 										 accessMethodName, accessMethodId);
 
-		heap_freetuple(atttuple);
+		ReleaseSysCache(atttuple);
 		attn++;
 	}
 }
@@ -507,13 +507,12 @@ GetAttrOpClass(IndexElem *attribute, Oid attrType,
 		doTypeCheck = false;
 	}
 
-	tuple = SearchSysCacheTuple(CLANAME,
-								PointerGetDatum(attribute->class),
-								0, 0, 0);
-	if (!HeapTupleIsValid(tuple))
+	opClassId = GetSysCacheOid(CLANAME,
+							   PointerGetDatum(attribute->class),
+							   0, 0, 0);
+	if (!OidIsValid(opClassId))
 		elog(ERROR, "DefineIndex: opclass \"%s\" not found",
 			 attribute->class);
-	opClassId = tuple->t_data->t_oid;
 
 	/*
 	 * Assume the opclass is supported by this index access method
@@ -532,10 +531,8 @@ GetAttrOpClass(IndexElem *attribute, Oid attrType,
 	scan = heap_beginscan(relation, false, SnapshotNow, 2, entry);
 
 	if (! HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
-	{
 		elog(ERROR, "DefineIndex: opclass \"%s\" not supported by access method \"%s\"",
 			 attribute->class, accessMethodName);
-	}
 
 	oprId = ((Form_pg_amop) GETSTRUCT(tuple))->amopopr;
 
@@ -557,9 +554,9 @@ GetAttrOpClass(IndexElem *attribute, Oid attrType,
 	 */
 	if (doTypeCheck)
 	{
-		tuple = SearchSysCacheTuple(OPEROID,
-									ObjectIdGetDatum(oprId),
-									0, 0, 0);
+		tuple = SearchSysCache(OPEROID,
+							   ObjectIdGetDatum(oprId),
+							   0, 0, 0);
 		if (HeapTupleIsValid(tuple))
 		{
 			Form_pg_operator optup = (Form_pg_operator) GETSTRUCT(tuple);
@@ -570,6 +567,7 @@ GetAttrOpClass(IndexElem *attribute, Oid attrType,
 				! IS_BINARY_COMPATIBLE(attrType, opInputType))
 				elog(ERROR, "DefineIndex: opclass \"%s\" does not accept datatype \"%s\"",
 					 attribute->class, typeidTypeName(attrType));
+			ReleaseSysCache(tuple);
 		}
 	}
 
@@ -580,15 +578,18 @@ static char *
 GetDefaultOpClass(Oid atttypid)
 {
 	HeapTuple	tuple;
+	char	   *result;
 
-	tuple = SearchSysCacheTuple(CLADEFTYPE,
-								ObjectIdGetDatum(atttypid),
-								0, 0, 0);
+	tuple = SearchSysCache(CLADEFTYPE,
+						   ObjectIdGetDatum(atttypid),
+						   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		return NULL;
 
-	return DatumGetCString(DirectFunctionCall1(nameout,
-			NameGetDatum(&((Form_pg_opclass) GETSTRUCT(tuple))->opcname)));
+	result = pstrdup(NameStr(((Form_pg_opclass) GETSTRUCT(tuple))->opcname));
+
+	ReleaseSysCache(tuple);
+	return result;
 }
 
 /*
@@ -605,21 +606,19 @@ RemoveIndex(char *name)
 {
 	HeapTuple	tuple;
 
-	tuple = SearchSysCacheTuple(RELNAME,
-								PointerGetDatum(name),
-								0, 0, 0);
-
+	tuple = SearchSysCache(RELNAME,
+						   PointerGetDatum(name),
+						   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "index \"%s\" does not exist", name);
 
 	if (((Form_pg_class) GETSTRUCT(tuple))->relkind != RELKIND_INDEX)
-	{
 		elog(ERROR, "relation \"%s\" is of type \"%c\"",
-			 name,
-			 ((Form_pg_class) GETSTRUCT(tuple))->relkind);
-	}
+			 name, ((Form_pg_class) GETSTRUCT(tuple))->relkind);
 
 	index_drop(tuple->t_data->t_oid);
+
+	ReleaseSysCache(tuple);
 }
 
 /*
@@ -644,22 +643,20 @@ ReindexIndex(const char *name, bool force /* currently unused */ )
 	if (IsTransactionBlock())
 		elog(ERROR, "REINDEX cannot run inside a BEGIN/END block");
 
-	tuple = SearchSysCacheTuple(RELNAME,
-								PointerGetDatum(name),
-								0, 0, 0);
-
+	tuple = SearchSysCache(RELNAME,
+						   PointerGetDatum(name),
+						   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "index \"%s\" does not exist", name);
 
 	if (((Form_pg_class) GETSTRUCT(tuple))->relkind != RELKIND_INDEX)
-	{
 		elog(ERROR, "relation \"%s\" is of type \"%c\"",
-			 name,
-			 ((Form_pg_class) GETSTRUCT(tuple))->relkind);
-	}
+			 name, ((Form_pg_class) GETSTRUCT(tuple))->relkind);
 
 	if (!reindex_index(tuple->t_data->t_oid, force))
 		elog(NOTICE, "index \"%s\" wasn't reindexed", name);
+
+	ReleaseSysCache(tuple);
 }
 
 /*
@@ -684,22 +681,20 @@ ReindexTable(const char *name, bool force)
 	if (IsTransactionBlock())
 		elog(ERROR, "REINDEX cannot run inside a BEGIN/END block");
 
-	tuple = SearchSysCacheTuple(RELNAME,
-								PointerGetDatum(name),
-								0, 0, 0);
-
+	tuple = SearchSysCache(RELNAME,
+						   PointerGetDatum(name),
+						   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "table \"%s\" does not exist", name);
 
 	if (((Form_pg_class) GETSTRUCT(tuple))->relkind != RELKIND_RELATION)
-	{
 		elog(ERROR, "relation \"%s\" is of type \"%c\"",
-			 name,
-			 ((Form_pg_class) GETSTRUCT(tuple))->relkind);
-	}
+			 name, ((Form_pg_class) GETSTRUCT(tuple))->relkind);
 
 	if (!reindex_relation(tuple->t_data->t_oid, force))
 		elog(NOTICE, "table \"%s\" wasn't reindexed", name);
+
+	ReleaseSysCache(tuple);
 }
 
 /*
diff --git a/src/backend/commands/proclang.c b/src/backend/commands/proclang.c
index ec8aec7005f..5d4d3f09bf7 100644
--- a/src/backend/commands/proclang.c
+++ b/src/backend/commands/proclang.c
@@ -48,7 +48,6 @@ void
 CreateProceduralLanguage(CreatePLangStmt *stmt)
 {
 	char		languageName[NAMEDATALEN];
-	HeapTuple	langTup;
 	HeapTuple	procTup;
 
 	Oid			typev[FUNC_MAX_ARGS];
@@ -77,10 +76,9 @@ CreateProceduralLanguage(CreatePLangStmt *stmt)
 	 */
 	case_translate_language_name(stmt->plname, languageName);
 
-	langTup = SearchSysCacheTuple(LANGNAME,
-								  PointerGetDatum(languageName),
-								  0, 0, 0);
-	if (HeapTupleIsValid(langTup))
+	if (SearchSysCacheExists(LANGNAME,
+							 PointerGetDatum(languageName),
+							 0, 0, 0))
 		elog(ERROR, "Language %s already exists", languageName);
 
 	/* ----------------
@@ -89,21 +87,17 @@ CreateProceduralLanguage(CreatePLangStmt *stmt)
 	 * ----------------
 	 */
 	memset(typev, 0, sizeof(typev));
-	procTup = SearchSysCacheTuple(PROCNAME,
-								  PointerGetDatum(stmt->plhandler),
-								  Int32GetDatum(0),
-								  PointerGetDatum(typev),
-								  0);
+	procTup = SearchSysCache(PROCNAME,
+							 PointerGetDatum(stmt->plhandler),
+							 Int32GetDatum(0),
+							 PointerGetDatum(typev),
+							 0);
 	if (!HeapTupleIsValid(procTup))
-	{
 		elog(ERROR, "PL handler function %s() doesn't exist",
 			 stmt->plhandler);
-	}
 	if (((Form_pg_proc) GETSTRUCT(procTup))->prorettype != InvalidOid)
-	{
 		elog(ERROR, "PL handler function %s() isn't of return type Opaque",
 			 stmt->plhandler);
-	}
 
 	/* ----------------
 	 * Insert the new language into pg_language
@@ -123,6 +117,8 @@ CreateProceduralLanguage(CreatePLangStmt *stmt)
 	values[i++] = DirectFunctionCall1(textin,
 									  CStringGetDatum(stmt->plcompiler));
 
+	ReleaseSysCache(procTup);
+
 	rel = heap_openr(LanguageRelationName, RowExclusiveLock);
 
 	tupDesc = rel->rd_att;
@@ -173,9 +169,9 @@ DropProceduralLanguage(DropPLangStmt *stmt)
 
 	rel = heap_openr(LanguageRelationName, RowExclusiveLock);
 
-	langTup = SearchSysCacheTupleCopy(LANGNAME,
-									  PointerGetDatum(languageName),
-									  0, 0, 0);
+	langTup = SearchSysCacheCopy(LANGNAME,
+								 PointerGetDatum(languageName),
+								 0, 0, 0);
 	if (!HeapTupleIsValid(langTup))
 		elog(ERROR, "Language %s doesn't exist", languageName);
 
diff --git a/src/backend/commands/remove.c b/src/backend/commands/remove.c
index a8ad2620ef7..fdcd0e7e744 100644
--- a/src/backend/commands/remove.c
+++ b/src/backend/commands/remove.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/remove.c,v 1.54 2000/10/16 17:08:05 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/remove.c,v 1.55 2000/11/16 22:30:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -73,11 +73,11 @@ RemoveOperator(char *operatorName,		/* operator name */
 
 	relation = heap_openr(OperatorRelationName, RowExclusiveLock);
 
-	tup = SearchSysCacheTupleCopy(OPERNAME,
-								  PointerGetDatum(operatorName),
-								  ObjectIdGetDatum(typeId1),
-								  ObjectIdGetDatum(typeId2),
-								  CharGetDatum(oprtype));
+	tup = SearchSysCacheCopy(OPERNAME,
+							 PointerGetDatum(operatorName),
+							 ObjectIdGetDatum(typeId1),
+							 ObjectIdGetDatum(typeId2),
+							 CharGetDatum(oprtype));
 
 	if (HeapTupleIsValid(tup))
 	{
@@ -254,14 +254,11 @@ RemoveType(char *typeName)		/* type name to be removed */
 
 	relation = heap_openr(TypeRelationName, RowExclusiveLock);
 
-	tup = SearchSysCacheTuple(TYPENAME,
-							  PointerGetDatum(typeName),
-							  0, 0, 0);
+	tup = SearchSysCache(TYPENAME,
+						 PointerGetDatum(typeName),
+						 0, 0, 0);
 	if (!HeapTupleIsValid(tup))
-	{
-		heap_close(relation, RowExclusiveLock);
 		elog(ERROR, "RemoveType: type '%s' does not exist", typeName);
-	}
 
 	typeOid = tup->t_data->t_oid;
 
@@ -271,19 +268,20 @@ RemoveType(char *typeName)		/* type name to be removed */
 
 	heap_delete(relation, &tup->t_self, NULL);
 
-	/* Now, Delete the "array of" that type */
+	ReleaseSysCache(tup);
+
+	/* Also, delete the "array of" that type */
 	shadow_type = makeArrayTypeName(typeName);
-	tup = SearchSysCacheTuple(TYPENAME,
-							  PointerGetDatum(shadow_type),
-							  0, 0, 0);
+	tup = SearchSysCache(TYPENAME,
+						 PointerGetDatum(shadow_type),
+						 0, 0, 0);
 	if (!HeapTupleIsValid(tup))
-	{
-		heap_close(relation, RowExclusiveLock);
 		elog(ERROR, "RemoveType: type '%s' does not exist", shadow_type);
-	}
 
 	heap_delete(relation, &tup->t_self, NULL);
 
+	ReleaseSysCache(tup);
+
 	heap_close(relation, RowExclusiveLock);
 }
 
@@ -321,12 +319,11 @@ RemoveFunction(char *functionName,		/* function name to be removed */
 			argList[i] = InvalidOid;
 		else
 		{
-			tup = SearchSysCacheTuple(TYPENAME,
-									  PointerGetDatum(typnam),
-									  0, 0, 0);
-			if (!HeapTupleIsValid(tup))
+			argList[i] = GetSysCacheOid(TYPENAME,
+										PointerGetDatum(typnam),
+										0, 0, 0);
+			if (!OidIsValid(argList[i]))
 				elog(ERROR, "RemoveFunction: type '%s' not found", typnam);
-			argList[i] = tup->t_data->t_oid;
 		}
 	}
 
@@ -337,11 +334,12 @@ RemoveFunction(char *functionName,		/* function name to be removed */
 	}
 
 	relation = heap_openr(ProcedureRelationName, RowExclusiveLock);
-	tup = SearchSysCacheTuple(PROCNAME,
-							  PointerGetDatum(functionName),
-							  Int32GetDatum(nargs),
-							  PointerGetDatum(argList),
-							  0);
+
+	tup = SearchSysCache(PROCNAME,
+						 PointerGetDatum(functionName),
+						 Int32GetDatum(nargs),
+						 PointerGetDatum(argList),
+						 0);
 
 	if (!HeapTupleIsValid(tup))
 		func_error("RemoveFunction", functionName, nargs, argList, NULL);
@@ -359,6 +357,8 @@ RemoveFunction(char *functionName,		/* function name to be removed */
 
 	heap_delete(relation, &tup->t_self, NULL);
 
+	ReleaseSysCache(tup);
+
 	heap_close(relation, RowExclusiveLock);
 }
 
@@ -370,7 +370,6 @@ RemoveAggregate(char *aggName, char *aggType)
 	Oid			basetypeID = InvalidOid;
 	bool		defined;
 
-
 	/*
 	 * if a basetype is passed in, then attempt to find an aggregate for
 	 * that specific type.
@@ -405,10 +404,11 @@ RemoveAggregate(char *aggName, char *aggType)
 	}
 
 	relation = heap_openr(AggregateRelationName, RowExclusiveLock);
-	tup = SearchSysCacheTuple(AGGNAME,
-							  PointerGetDatum(aggName),
-							  ObjectIdGetDatum(basetypeID),
-							  0, 0);
+
+	tup = SearchSysCache(AGGNAME,
+						 PointerGetDatum(aggName),
+						 ObjectIdGetDatum(basetypeID),
+						 0, 0);
 
 	if (!HeapTupleIsValid(tup))
 	{
@@ -431,5 +431,7 @@ RemoveAggregate(char *aggName, char *aggType)
 
 	heap_delete(relation, &tup->t_self, NULL);
 
+	ReleaseSysCache(tup);
+
 	heap_close(relation, RowExclusiveLock);
 }
diff --git a/src/backend/commands/rename.c b/src/backend/commands/rename.c
index 6a9de4abf00..3722948047b 100644
--- a/src/backend/commands/rename.c
+++ b/src/backend/commands/rename.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/rename.c,v 1.52 2000/11/08 22:09:57 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/rename.c,v 1.53 2000/11/16 22:30:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -58,8 +58,7 @@ renameatt(char *relname,
 	Relation	targetrelation;
 	Relation	attrelation;
 	HeapTuple	reltup,
-				oldatttup,
-				newatttup;
+				atttup;
 	Oid			relid;
 
 	/*
@@ -113,9 +112,9 @@ renameatt(char *relname,
 
 			if (childrelid == relid)
 				continue;
-			reltup = SearchSysCacheTuple(RELOID,
-										 ObjectIdGetDatum(childrelid),
-										 0, 0, 0);
+			reltup = SearchSysCache(RELOID,
+									ObjectIdGetDatum(childrelid),
+									0, 0, 0);
 			if (!HeapTupleIsValid(reltup))
 			{
 				elog(ERROR, "renameatt: can't find catalog entry for inheriting class with oid %u",
@@ -125,6 +124,7 @@ renameatt(char *relname,
 			StrNCpy(childname,
 					NameStr(((Form_pg_class) GETSTRUCT(reltup))->relname),
 					NAMEDATALEN);
+			ReleaseSysCache(reltup);
 			/* note we need not recurse again! */
 			renameatt(childname, oldattname, newattname, 0);
 		}
@@ -132,42 +132,38 @@ renameatt(char *relname,
 
 	attrelation = heap_openr(AttributeRelationName, RowExclusiveLock);
 
-	oldatttup = SearchSysCacheTupleCopy(ATTNAME,
-										ObjectIdGetDatum(relid),
-										PointerGetDatum(oldattname),
-										0, 0);
-	if (!HeapTupleIsValid(oldatttup))
+	atttup = SearchSysCacheCopy(ATTNAME,
+								ObjectIdGetDatum(relid),
+								PointerGetDatum(oldattname),
+								0, 0);
+	if (!HeapTupleIsValid(atttup))
 		elog(ERROR, "renameatt: attribute \"%s\" does not exist", oldattname);
 
-	if (((Form_pg_attribute) GETSTRUCT(oldatttup))->attnum < 0)
+	if (((Form_pg_attribute) GETSTRUCT(atttup))->attnum < 0)
 		elog(ERROR, "renameatt: system attribute \"%s\" not renamed", oldattname);
 
-	newatttup = SearchSysCacheTuple(ATTNAME,
-									ObjectIdGetDatum(relid),
-									PointerGetDatum(newattname),
-									0, 0);
 	/* should not already exist */
-	if (HeapTupleIsValid(newatttup))
-	{
-		heap_freetuple(oldatttup);
+	if (SearchSysCacheExists(ATTNAME,
+							 ObjectIdGetDatum(relid),
+							 PointerGetDatum(newattname),
+							 0, 0))
 		elog(ERROR, "renameatt: attribute \"%s\" exists", newattname);
-	}
 
-	StrNCpy(NameStr(((Form_pg_attribute) GETSTRUCT(oldatttup))->attname),
+	StrNCpy(NameStr(((Form_pg_attribute) GETSTRUCT(atttup))->attname),
 			newattname, NAMEDATALEN);
 
-	heap_update(attrelation, &oldatttup->t_self, oldatttup, NULL);
+	heap_update(attrelation, &atttup->t_self, atttup, NULL);
 
 	/* keep system catalog indices current */
 	{
 		Relation	irelations[Num_pg_attr_indices];
 
 		CatalogOpenIndices(Num_pg_attr_indices, Name_pg_attr_indices, irelations);
-		CatalogIndexInsert(irelations, Num_pg_attr_indices, attrelation, oldatttup);
+		CatalogIndexInsert(irelations, Num_pg_attr_indices, attrelation, atttup);
 		CatalogCloseIndices(Num_pg_attr_indices, irelations);
 	}
 
-	heap_freetuple(oldatttup);
+	heap_freetuple(atttup);
 	heap_close(attrelation, RowExclusiveLock);
 }
 
@@ -179,7 +175,7 @@ renamerel(const char *oldrelname, const char *newrelname)
 {
 	Relation	targetrelation;
 	Relation	relrelation;	/* for RELATION relation */
-	HeapTuple	oldreltup;
+	HeapTuple	reltup;
 	Oid			reloid;
 	char		relkind;
 	Relation	irelations[Num_pg_class_indices];
@@ -238,27 +234,27 @@ renamerel(const char *oldrelname, const char *newrelname)
 	 */
 	relrelation = heap_openr(RelationRelationName, RowExclusiveLock);
 
-	oldreltup = SearchSysCacheTupleCopy(RELNAME,
-										PointerGetDatum(oldrelname),
-										0, 0, 0);
-	if (!HeapTupleIsValid(oldreltup))
+	reltup = SearchSysCacheCopy(RELNAME,
+								PointerGetDatum(oldrelname),
+								0, 0, 0);
+	if (!HeapTupleIsValid(reltup))
 		elog(ERROR, "renamerel: relation \"%s\" does not exist", oldrelname);
 
 	if (RelnameFindRelid(newrelname) != InvalidOid)
 		elog(ERROR, "renamerel: relation \"%s\" exists", newrelname);
 
 	/*
-	 * Update pg_class tuple with new relname.  (Scribbling on oldreltup
+	 * Update pg_class tuple with new relname.  (Scribbling on reltup
 	 * is OK because it's a copy...)
 	 */
-	StrNCpy(NameStr(((Form_pg_class) GETSTRUCT(oldreltup))->relname),
+	StrNCpy(NameStr(((Form_pg_class) GETSTRUCT(reltup))->relname),
 			newrelname, NAMEDATALEN);
 
-	heap_update(relrelation, &oldreltup->t_self, oldreltup, NULL);
+	heap_update(relrelation, &reltup->t_self, reltup, NULL);
 
 	/* keep the system catalog indices current */
 	CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, irelations);
-	CatalogIndexInsert(irelations, Num_pg_class_indices, relrelation, oldreltup);
+	CatalogIndexInsert(irelations, Num_pg_class_indices, relrelation, reltup);
 	CatalogCloseIndices(Num_pg_class_indices, irelations);
 
 	heap_close(relrelation, NoLock);
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 33340291e1c..22dfcac0524 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.79 2000/11/08 22:09:57 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.80 2000/11/16 22:30:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -154,11 +154,11 @@ CreateTrigger(CreateTrigStmt *stmt)
 	 * Find and validate the trigger function.
 	 */
 	MemSet(fargtypes, 0, FUNC_MAX_ARGS * sizeof(Oid));
-	tuple = SearchSysCacheTuple(PROCNAME,
-								PointerGetDatum(stmt->funcname),
-								Int32GetDatum(0),
-								PointerGetDatum(fargtypes),
-								0);
+	tuple = SearchSysCache(PROCNAME,
+						   PointerGetDatum(stmt->funcname),
+						   Int32GetDatum(0),
+						   PointerGetDatum(fargtypes),
+						   0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "CreateTrigger: function %s() does not exist",
 			 stmt->funcname);
@@ -167,6 +167,8 @@ CreateTrigger(CreateTrigStmt *stmt)
 			 stmt->funcname);
 	funcoid = tuple->t_data->t_oid;
 	funclang = ((Form_pg_proc) GETSTRUCT(tuple))->prolang;
+	ReleaseSysCache(tuple);
+
 	if (funclang != ClanguageId &&
 		funclang != NEWClanguageId &&
 		funclang != INTERNALlanguageId &&
@@ -174,14 +176,15 @@ CreateTrigger(CreateTrigStmt *stmt)
 	{
 		HeapTuple	langTup;
 
-		langTup = SearchSysCacheTuple(LANGOID,
-									  ObjectIdGetDatum(funclang),
-									  0, 0, 0);
+		langTup = SearchSysCache(LANGOID,
+								 ObjectIdGetDatum(funclang),
+								 0, 0, 0);
 		if (!HeapTupleIsValid(langTup))
 			elog(ERROR, "CreateTrigger: cache lookup for PL %u failed",
 				 funclang);
 		if (((Form_pg_language) GETSTRUCT(langTup))->lanispl == false)
 			elog(ERROR, "CreateTrigger: only builtin, C and PL functions are supported");
+		ReleaseSysCache(langTup);
 	}
 
 	/*
@@ -268,9 +271,9 @@ CreateTrigger(CreateTrigStmt *stmt)
 	 * rebuild relcache entries.
 	 */
 	pgrel = heap_openr(RelationRelationName, RowExclusiveLock);
-	tuple = SearchSysCacheTupleCopy(RELNAME,
-									PointerGetDatum(stmt->relname),
-									0, 0, 0);
+	tuple = SearchSysCacheCopy(RELNAME,
+							   PointerGetDatum(stmt->relname),
+							   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "CreateTrigger: relation %s not found in pg_class",
 			 stmt->relname);
@@ -353,9 +356,9 @@ DropTrigger(DropTrigStmt *stmt)
 	 * rebuild relcache entries.
 	 */
 	pgrel = heap_openr(RelationRelationName, RowExclusiveLock);
-	tuple = SearchSysCacheTupleCopy(RELNAME,
-									PointerGetDatum(stmt->relname),
-									0, 0, 0);
+	tuple = SearchSysCacheCopy(RELNAME,
+							   PointerGetDatum(stmt->relname),
+							   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "DropTrigger: relation %s not found in pg_class",
 			 stmt->relname);
@@ -426,9 +429,9 @@ RelationRemoveTriggers(Relation rel)
 		Relation	ridescs[Num_pg_class_indices];
 
 		pgrel = heap_openr(RelationRelationName, RowExclusiveLock);
-		tup = SearchSysCacheTupleCopy(RELOID,
-									  RelationGetRelid(rel),
-									  0, 0, 0);
+		tup = SearchSysCacheCopy(RELOID,
+								 RelationGetRelid(rel),
+								 0, 0, 0);
 		if (!HeapTupleIsValid(tup))
 			elog(ERROR, "RelationRemoveTriggers: relation %u not found in pg_class",
 				 RelationGetRelid(rel));
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index 55064bf5126..a33098b2e0b 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/src/backend/commands/user.c,v 1.69 2000/10/19 03:55:51 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/user.c,v 1.70 2000/11/16 22:30:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -363,9 +363,9 @@ AlterUser(AlterUserStmt *stmt)
 	pg_shadow_rel = heap_openr(ShadowRelationName, AccessExclusiveLock);
 	pg_shadow_dsc = RelationGetDescr(pg_shadow_rel);
 
-	tuple = SearchSysCacheTuple(SHADOWNAME,
-								PointerGetDatum(stmt->user),
-								0, 0, 0);
+	tuple = SearchSysCache(SHADOWNAME,
+						   PointerGetDatum(stmt->user),
+						   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 	{
 		heap_close(pg_shadow_rel, AccessExclusiveLock);
@@ -470,10 +470,13 @@ AlterUser(AlterUserStmt *stmt)
 		CatalogOpenIndices(Num_pg_shadow_indices,
 						   Name_pg_shadow_indices, idescs);
 		CatalogIndexInsert(idescs, Num_pg_shadow_indices, pg_shadow_rel,
-						   tuple);
+						   new_tuple);
 		CatalogCloseIndices(Num_pg_shadow_indices, idescs);
 	}
 
+	ReleaseSysCache(tuple);
+	heap_freetuple(new_tuple);
+
 	/*
 	 * Write the updated pg_shadow data to the flat password file.
 	 */
@@ -525,9 +528,9 @@ DropUser(DropUserStmt *stmt)
 		int32		usesysid;
 		const char *user = strVal(lfirst(item));
 
-		tuple = SearchSysCacheTuple(SHADOWNAME,
-									PointerGetDatum(user),
-									0, 0, 0);
+		tuple = SearchSysCache(SHADOWNAME,
+							   PointerGetDatum(user),
+							   0, 0, 0);
 		if (!HeapTupleIsValid(tuple))
 		{
 			heap_close(pg_shadow_rel, AccessExclusiveLock);
@@ -579,6 +582,8 @@ DropUser(DropUserStmt *stmt)
 		 */
 		heap_delete(pg_shadow_rel, &tuple->t_self, NULL);
 
+		ReleaseSysCache(tuple);
+
 		/*
 		 * Remove user from groups
 		 *
@@ -633,24 +638,21 @@ CheckPgUserAclNotNull()
 {
 	HeapTuple	htup;
 
-	htup = SearchSysCacheTuple(RELNAME,
-							   PointerGetDatum(ShadowRelationName),
-							   0, 0, 0);
+	htup = SearchSysCache(RELNAME,
+						  PointerGetDatum(ShadowRelationName),
+						  0, 0, 0);
 	if (!HeapTupleIsValid(htup))
-	{
-		/* BIG problem */
-		elog(ERROR, "IsPgUserAclNull: \"%s\" not found",
+		elog(ERROR, "CheckPgUserAclNotNull: \"%s\" not found",
 			 ShadowRelationName);
-	}
 
 	if (heap_attisnull(htup, Anum_pg_class_relacl))
-	{
 		elog(ERROR,
 			 "To use passwords, you have to revoke permissions on %s "
 			 "so normal users cannot read the passwords. "
 			 "Try 'REVOKE ALL ON \"%s\" FROM PUBLIC'.",
 			 ShadowRelationName, ShadowRelationName);
-	}
+
+	ReleaseSysCache(htup);
 }
 
 
@@ -716,24 +718,21 @@ CreateGroup(CreateGroupStmt *stmt)
 	/*
 	 * Translate the given user names to ids
 	 */
-
 	foreach(item, stmt->initUsers)
 	{
 		const char *groupuser = strVal(lfirst(item));
 		Value	   *v;
 
-		tuple = SearchSysCacheTuple(SHADOWNAME,
-									PointerGetDatum(groupuser),
-									0, 0, 0);
+		tuple = SearchSysCache(SHADOWNAME,
+							   PointerGetDatum(groupuser),
+							   0, 0, 0);
 		if (!HeapTupleIsValid(tuple))
-		{
-			heap_close(pg_group_rel, AccessExclusiveLock);
 			elog(ERROR, "CREATE GROUP: user \"%s\" does not exist", groupuser);
-		}
 
 		v = makeInteger(((Form_pg_shadow) GETSTRUCT(tuple))->usesysid);
 		if (!member(v, newlist))
 			newlist = lcons(v, newlist);
+		ReleaseSysCache(tuple);
 	}
 
 	/* build an array to insert */
@@ -817,20 +816,19 @@ AlterGroup(AlterGroupStmt *stmt, const char *tag)
 	pg_group_dsc = RelationGetDescr(pg_group_rel);
 
 	/*
-	 * Verify that group exists. If we find a tuple, will take that the
-	 * rest of the way and make our modifications on it.
+	 * Fetch existing tuple for group.
 	 */
-	if (!HeapTupleIsValid(group_tuple = SearchSysCacheTupleCopy(GRONAME, PointerGetDatum(stmt->name), 0, 0, 0)))
-	{
-		heap_close(pg_group_rel, AccessExclusiveLock);
+	group_tuple = SearchSysCache(GRONAME,
+								 PointerGetDatum(stmt->name),
+								 0, 0, 0);
+	if (!HeapTupleIsValid(group_tuple))
 		elog(ERROR, "%s: group \"%s\" does not exist", tag, stmt->name);
-	}
-
-	AssertState(stmt->action == +1 || stmt->action == -1);
 
 	/*
 	 * Now decide what to do.
 	 */
+	AssertState(stmt->action == +1 || stmt->action == -1);
+
 	if (stmt->action == +1)		/* add users, might also be invoked by
 								 * create user */
 	{
@@ -876,15 +874,14 @@ AlterGroup(AlterGroupStmt *stmt, const char *tag)
 			if (strcmp(tag, "ALTER GROUP") == 0)
 			{
 				/* Get the uid of the proposed user to add. */
-				tuple = SearchSysCacheTuple(SHADOWNAME,
-								   PointerGetDatum(strVal(lfirst(item))),
-											0, 0, 0);
+				tuple = SearchSysCache(SHADOWNAME,
+									   PointerGetDatum(strVal(lfirst(item))),
+									   0, 0, 0);
 				if (!HeapTupleIsValid(tuple))
-				{
-					heap_close(pg_group_rel, AccessExclusiveLock);
-					elog(ERROR, "%s: user \"%s\" does not exist", tag, strVal(lfirst(item)));
-				}
+					elog(ERROR, "%s: user \"%s\" does not exist",
+						 tag, strVal(lfirst(item)));
 				v = makeInteger(((Form_pg_shadow) GETSTRUCT(tuple))->usesysid);
+				ReleaseSysCache(tuple);
 			}
 			else if (strcmp(tag, "CREATE USER") == 0)
 			{
@@ -999,15 +996,13 @@ AlterGroup(AlterGroupStmt *stmt, const char *tag)
 				if (!is_dropuser)
 				{
 					/* Get the uid of the proposed user to drop. */
-					tuple = SearchSysCacheTuple(SHADOWNAME,
-								   PointerGetDatum(strVal(lfirst(item))),
-												0, 0, 0);
+					tuple = SearchSysCache(SHADOWNAME,
+										   PointerGetDatum(strVal(lfirst(item))),
+										   0, 0, 0);
 					if (!HeapTupleIsValid(tuple))
-					{
-						heap_close(pg_group_rel, AccessExclusiveLock);
 						elog(ERROR, "ALTER GROUP: user \"%s\" does not exist", strVal(lfirst(item)));
-					}
 					v = makeInteger(((Form_pg_shadow) GETSTRUCT(tuple))->usesysid);
+					ReleaseSysCache(tuple);
 				}
 				else
 				{
@@ -1056,9 +1051,9 @@ AlterGroup(AlterGroupStmt *stmt, const char *tag)
 		}						/* endif group not null */
 	}							/* endif alter group drop user */
 
-	heap_close(pg_group_rel, AccessExclusiveLock);
+	ReleaseSysCache(group_tuple);
 
-	pfree(group_tuple);
+	heap_close(pg_group_rel, AccessExclusiveLock);
 }
 
 
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 403d80942de..3aeae1409bd 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.172 2000/11/16 05:50:59 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.173 2000/11/16 22:30:19 tgl Exp $
  *
 
  *-------------------------------------------------------------------------
@@ -356,7 +356,6 @@ getrels(NameData *VacRelP)
 static void
 vacuum_rel(Oid relid, bool analyze, bool is_toastrel)
 {
-	HeapTuple	tuple;
 	Relation	onerel;
 	VacPageListData vacuum_pages; /* List of pages to vacuum and/or clean
 								 * indices */
@@ -384,10 +383,9 @@ vacuum_rel(Oid relid, bool analyze, bool is_toastrel)
 	 * Race condition -- if the pg_class tuple has gone away since the
 	 * last time we saw it, we don't need to vacuum it.
 	 */
-	tuple = SearchSysCacheTuple(RELOID,
-								ObjectIdGetDatum(relid),
-								0, 0, 0);
-	if (!HeapTupleIsValid(tuple))
+	if (!SearchSysCacheExists(RELOID,
+							  ObjectIdGetDatum(relid),
+							  0, 0, 0))
 	{
 		if (!is_toastrel)
 			CommitTransactionCommand();
@@ -2237,17 +2235,17 @@ update_relstats(Oid relid, int num_pages, int num_tuples, bool hasindex,
 	 */
 	rd = heap_openr(RelationRelationName, RowExclusiveLock);
 
-	ctup = SearchSysCacheTupleCopy(RELOID,
-								   ObjectIdGetDatum(relid),
-								   0, 0, 0);
+	ctup = SearchSysCache(RELOID,
+						  ObjectIdGetDatum(relid),
+						  0, 0, 0);
 	if (!HeapTupleIsValid(ctup))
 		elog(ERROR, "pg_class entry for relid %u vanished during vacuuming",
 			 relid);
 
 	/* get the buffer cache tuple */
 	rtup.t_self = ctup->t_self;
+	ReleaseSysCache(ctup);
 	heap_fetch(rd, SnapshotNow, &rtup, &buffer);
-	heap_freetuple(ctup);
 
 	/* overwrite the existing statistics in the tuple */
 	pgcform = (Form_pg_class) GETSTRUCT(&rtup);
@@ -2481,13 +2479,14 @@ get_index_desc(Relation onerel, int nindices, Relation *Irel)
 
 	for (i = 0; i < nindices; i++)
 	{
-		cachetuple = SearchSysCacheTuple(INDEXRELID,
+		cachetuple = SearchSysCache(INDEXRELID,
 							 ObjectIdGetDatum(RelationGetRelid(Irel[i])),
-										 0, 0, 0);
+									0, 0, 0);
 		if (!HeapTupleIsValid(cachetuple))
 			elog(ERROR, "get_index_desc: index %u not found",
 				 RelationGetRelid(Irel[i]));
 		indexInfo[i] = BuildIndexInfo(cachetuple);
+		ReleaseSysCache(cachetuple);
 	}
 
 	return indexInfo;