Restructure indexscan API (index_beginscan, index_getnext) per

yesterday's proposal to pghackers.  Also remove unnecessary parameters
to heap_beginscan, heap_rescan.  I modified pg_proc.h to reflect the
new numbers of parameters for the AM interface routines, but did not
force an initdb because nothing actually looks at those fields.

10 files changed, 123 insertions, 176 deletions

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f4c8e6919e..c015043843 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 1.32 2002/04/16 23:08:10 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.33 2002/05/20 23:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -524,8 +524,8 @@ acquire_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 	/*
 	 * Do a simple linear scan until we reach the target number of rows.
 	 */
-	scan = heap_beginscan(onerel, false, SnapshotNow, 0, NULL);
-	while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+	scan = heap_beginscan(onerel, SnapshotNow, 0, NULL);
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		rows[numrows++] = heap_copytuple(tuple);
 		if (numrows >= targrows)
diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c
index 8193174aec..271be15119 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 1.84 2002/05/05 00:03:28 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/async.c,v 1.85 2002/05/20 23:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -204,8 +204,8 @@ Async_Listen(char *relname, int pid)
 	lRel = heap_openr(ListenerRelationName, AccessExclusiveLock);
 
 	/* Detect whether we are already listening on this relname */
-	scan = heap_beginscan(lRel, 0, SnapshotNow, 0, (ScanKey) NULL);
-	while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+	scan = heap_beginscan(lRel, SnapshotNow, 0, (ScanKey) NULL);
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Form_pg_listener listener = (Form_pg_listener) GETSTRUCT(tuple);
 
@@ -305,8 +305,8 @@ Async_Unlisten(char *relname, int pid)
 
 	lRel = heap_openr(ListenerRelationName, AccessExclusiveLock);
 
-	scan = heap_beginscan(lRel, 0, SnapshotNow, 0, (ScanKey) NULL);
-	while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+	scan = heap_beginscan(lRel, SnapshotNow, 0, (ScanKey) NULL);
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Form_pg_listener listener = (Form_pg_listener) GETSTRUCT(tuple);
 
@@ -369,9 +369,9 @@ Async_UnlistenAll(void)
 						   Anum_pg_listener_pid,
 						   F_INT4EQ,
 						   Int32GetDatum(MyProcPid));
-	scan = heap_beginscan(lRel, 0, SnapshotNow, 1, key);
+	scan = heap_beginscan(lRel, SnapshotNow, 1, key);
 
-	while (HeapTupleIsValid(lTuple = heap_getnext(scan, 0)))
+	while ((lTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 		simple_heap_delete(lRel, &lTuple->t_self);
 
 	heap_endscan(scan);
@@ -472,9 +472,9 @@ AtCommit_Notify(void)
 
 	lRel = heap_openr(ListenerRelationName, AccessExclusiveLock);
 	tdesc = RelationGetDescr(lRel);
-	scan = heap_beginscan(lRel, 0, SnapshotNow, 0, (ScanKey) NULL);
+	scan = heap_beginscan(lRel, SnapshotNow, 0, (ScanKey) NULL);
 
-	while (HeapTupleIsValid(lTuple = heap_getnext(scan, 0)))
+	while ((lTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Form_pg_listener listener = (Form_pg_listener) GETSTRUCT(lTuple);
 		char	   *relname = NameStr(listener->relname);
@@ -773,7 +773,7 @@ ProcessIncomingNotify(void)
 						   Anum_pg_listener_pid,
 						   F_INT4EQ,
 						   Int32GetDatum(MyProcPid));
-	scan = heap_beginscan(lRel, 0, SnapshotNow, 1, key);
+	scan = heap_beginscan(lRel, SnapshotNow, 1, key);
 
 	/* Prepare data for rewriting 0 into notification field */
 	nulls[0] = nulls[1] = nulls[2] = ' ';
@@ -782,7 +782,7 @@ ProcessIncomingNotify(void)
 	value[0] = value[1] = value[2] = (Datum) 0;
 	value[Anum_pg_listener_notify - 1] = Int32GetDatum(0);
 
-	while (HeapTupleIsValid(lTuple = heap_getnext(scan, 0)))
+	while ((lTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Form_pg_listener listener = (Form_pg_listener) GETSTRUCT(lTuple);
 		char	   *relname = NameStr(listener->relname);
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 01a45b0625..a6215cb23f 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 1.79 2002/04/27 21:24:34 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.80 2002/05/20 23:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -217,7 +217,7 @@ rebuildheap(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex)
 				LocalOldHeap,
 				LocalOldIndex;
 	IndexScanDesc ScanDesc;
-	RetrieveIndexResult ScanResult;
+	HeapTuple	LocalHeapTuple;
 
 	/*
 	 * Open the relations I need. Scan through the OldHeap on the OldIndex
@@ -227,36 +227,24 @@ rebuildheap(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex)
 	LocalOldHeap = heap_open(OIDOldHeap, AccessExclusiveLock);
 	LocalOldIndex = index_open(OIDOldIndex);
 
-	ScanDesc = index_beginscan(LocalOldIndex, false, 0, (ScanKey) NULL);
+	ScanDesc = index_beginscan(LocalOldHeap, LocalOldIndex,
+							   SnapshotNow, 0, (ScanKey) NULL);
 
-	while ((ScanResult = index_getnext(ScanDesc, ForwardScanDirection)) != NULL)
+	while ((LocalHeapTuple = index_getnext(ScanDesc, ForwardScanDirection)) != NULL)
 	{
-		HeapTupleData LocalHeapTuple;
-		Buffer		LocalBuffer;
+		/*
+		 * We must copy the tuple because heap_insert() will overwrite
+		 * the commit-status fields of the tuple it's handed, and the
+		 * retrieved tuple will actually be in a disk buffer!  Thus,
+		 * the source relation would get trashed, which is bad news if
+		 * we abort later on.  (This was a bug in releases thru 7.0)
+		 */
+		HeapTuple	copiedTuple = heap_copytuple(LocalHeapTuple);
+
+		heap_insert(LocalNewHeap, copiedTuple);
+		heap_freetuple(copiedTuple);
 
 		CHECK_FOR_INTERRUPTS();
-
-		LocalHeapTuple.t_self = ScanResult->heap_iptr;
-		LocalHeapTuple.t_datamcxt = NULL;
-		LocalHeapTuple.t_data = NULL;
-		heap_fetch(LocalOldHeap, SnapshotNow, &LocalHeapTuple, &LocalBuffer,
-				   ScanDesc);
-		if (LocalHeapTuple.t_data != NULL)
-		{
-			/*
-			 * We must copy the tuple because heap_insert() will overwrite
-			 * the commit-status fields of the tuple it's handed, and the
-			 * retrieved tuple will actually be in a disk buffer!  Thus,
-			 * the source relation would get trashed, which is bad news if
-			 * we abort later on.  (This was a bug in releases thru 7.0)
-			 */
-			HeapTuple	copiedTuple = heap_copytuple(&LocalHeapTuple);
-
-			ReleaseBuffer(LocalBuffer);
-			heap_insert(LocalNewHeap, copiedTuple);
-			heap_freetuple(copiedTuple);
-		}
-		pfree(ScanResult);
 	}
 
 	index_endscan(ScanDesc);
diff --git a/src/backend/commands/comment.c b/src/backend/commands/comment.c
index 1c12061ba5..9d48e33b2c 100644
--- a/src/backend/commands/comment.c
+++ b/src/backend/commands/comment.c
@@ -7,7 +7,7 @@
  * Copyright (c) 1999-2001, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/comment.c,v 1.46 2002/05/13 17:45:30 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/comment.c,v 1.47 2002/05/20 23:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -122,12 +122,9 @@ void
 CreateComments(Oid oid, Oid classoid, int32 subid, char *comment)
 {
 	Relation	description;
-	Relation	descriptionindex;
 	ScanKeyData skey[3];
-	IndexScanDesc sd;
-	RetrieveIndexResult indexRes;
-	HeapTupleData oldtuple;
-	Buffer		buffer;
+	SysScanDesc sd;
+	HeapTuple	oldtuple;
 	HeapTuple	newtuple = NULL;
 	Datum		values[Natts_pg_description];
 	char		nulls[Natts_pg_description];
@@ -153,11 +150,6 @@ CreateComments(Oid oid, Oid classoid, int32 subid, char *comment)
 		values[i++] = DirectFunctionCall1(textin, CStringGetDatum(comment));
 	}
 
-	/* Open pg_description and its index */
-
-	description = heap_openr(DescriptionRelationName, RowExclusiveLock);
-	descriptionindex = index_openr(DescriptionObjIndex);
-
 	/* Use the index to search for a matching old tuple */
 
 	ScanKeyEntryInitialize(&skey[0],
@@ -178,40 +170,32 @@ CreateComments(Oid oid, Oid classoid, int32 subid, char *comment)
 						   (RegProcedure) F_INT4EQ,
 						   Int32GetDatum(subid));
 
-	sd = index_beginscan(descriptionindex, false, 3, skey);
+	description = heap_openr(DescriptionRelationName, RowExclusiveLock);
 
-	oldtuple.t_datamcxt = CurrentMemoryContext;
-	oldtuple.t_data = NULL;
+	sd = systable_beginscan(description, DescriptionObjIndex, true,
+							SnapshotNow, 3, skey);
 
-	while ((indexRes = index_getnext(sd, ForwardScanDirection)))
+	while ((oldtuple = systable_getnext(sd)) != NULL)
 	{
-		oldtuple.t_self = indexRes->heap_iptr;
-		heap_fetch(description, SnapshotNow, &oldtuple, &buffer, sd);
-		pfree(indexRes);
-
-		if (oldtuple.t_data == NULL)
-			continue;			/* time qual failed */
-
 		/* Found the old tuple, so delete or update it */
 
 		if (comment == NULL)
-			simple_heap_delete(description, &oldtuple.t_self);
+			simple_heap_delete(description, &oldtuple->t_self);
 		else
 		{
-			newtuple = heap_modifytuple(&oldtuple, description, values,
+			newtuple = heap_modifytuple(oldtuple, description, values,
 										nulls, replaces);
-			simple_heap_update(description, &oldtuple.t_self, newtuple);
+			simple_heap_update(description, &oldtuple->t_self, newtuple);
 		}
 
-		ReleaseBuffer(buffer);
 		break;					/* Assume there can be only one match */
 	}
 
-	index_endscan(sd);
+	systable_endscan(sd);
 
 	/* If we didn't find an old tuple, insert a new one */
 
-	if (oldtuple.t_data == NULL && comment != NULL)
+	if (newtuple == NULL && comment != NULL)
 	{
 		newtuple = heap_formtuple(RelationGetDescr(description),
 								  values, nulls);
@@ -237,7 +221,6 @@ CreateComments(Oid oid, Oid classoid, int32 subid, char *comment)
 
 	/* Done */
 
-	index_close(descriptionindex);
 	heap_close(description, NoLock);
 }
 
@@ -252,17 +235,9 @@ void
 DeleteComments(Oid oid, Oid classoid)
 {
 	Relation	description;
-	Relation	descriptionindex;
 	ScanKeyData skey[2];
-	IndexScanDesc sd;
-	RetrieveIndexResult indexRes;
-	HeapTupleData oldtuple;
-	Buffer		buffer;
-
-	/* Open pg_description and its index */
-
-	description = heap_openr(DescriptionRelationName, RowExclusiveLock);
-	descriptionindex = index_openr(DescriptionObjIndex);
+	SysScanDesc	sd;
+	HeapTuple	oldtuple;
 
 	/* Use the index to search for all matching old tuples */
 
@@ -278,26 +253,19 @@ DeleteComments(Oid oid, Oid classoid)
 						   (RegProcedure) F_OIDEQ,
 						   ObjectIdGetDatum(classoid));
 
-	sd = index_beginscan(descriptionindex, false, 2, skey);
-
-	while ((indexRes = index_getnext(sd, ForwardScanDirection)))
-	{
-		oldtuple.t_self = indexRes->heap_iptr;
-		heap_fetch(description, SnapshotNow, &oldtuple, &buffer, sd);
-		pfree(indexRes);
-
-		if (oldtuple.t_data == NULL)
-			continue;			/* time qual failed */
+	description = heap_openr(DescriptionRelationName, RowExclusiveLock);
 
-		simple_heap_delete(description, &oldtuple.t_self);
+	sd = systable_beginscan(description, DescriptionObjIndex, true,
+							SnapshotNow, 2, skey);
 
-		ReleaseBuffer(buffer);
+	while ((oldtuple = systable_getnext(sd)) != NULL)
+	{
+		simple_heap_delete(description, &oldtuple->t_self);
 	}
 
 	/* Done */
 
-	index_endscan(sd);
-	index_close(descriptionindex);
+	systable_endscan(sd);
 	heap_close(description, NoLock);
 }
 
@@ -449,8 +417,8 @@ CommentDatabase(List *qualname, char *comment)
 	pg_database = heap_openr(DatabaseRelationName, AccessShareLock);
 	ScanKeyEntryInitialize(&entry, 0, Anum_pg_database_datname,
 						   F_NAMEEQ, CStringGetDatum(database));
-	scan = heap_beginscan(pg_database, 0, SnapshotNow, 1, &entry);
-	dbtuple = heap_getnext(scan, 0);
+	scan = heap_beginscan(pg_database, SnapshotNow, 1, &entry);
+	dbtuple = heap_getnext(scan, ForwardScanDirection);
 
 	/* Validate database exists, and fetch the db oid */
 
@@ -566,10 +534,10 @@ CommentRule(List *qualname, char *comment)
 							   PointerGetDatum(rulename));
 
 		RewriteRelation = heap_openr(RewriteRelationName, AccessShareLock);
-		scanDesc = heap_beginscan(RewriteRelation,
-								  0, SnapshotNow, 1, &scanKeyData);
+		scanDesc = heap_beginscan(RewriteRelation, SnapshotNow,
+								  1, &scanKeyData);
 
-		tuple = heap_getnext(scanDesc, 0);
+		tuple = heap_getnext(scanDesc, ForwardScanDirection);
 		if (HeapTupleIsValid(tuple))
 		{
 			reloid = ((Form_pg_rewrite) GETSTRUCT(tuple))->ev_class;
@@ -581,7 +549,8 @@ CommentRule(List *qualname, char *comment)
 			reloid = ruleoid = 0; /* keep compiler quiet */
 		}
 
-		if (HeapTupleIsValid(tuple = heap_getnext(scanDesc, 0)))
+		if (HeapTupleIsValid(tuple = heap_getnext(scanDesc,
+												  ForwardScanDirection)))
 			elog(ERROR, "There are multiple rules \"%s\""
 				 "\n\tPlease specify a relation name as well as a rule name",
 				 rulename);
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 1ab3ae14fc..1f9aef8fc0 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 1.153 2002/04/27 03:45:00 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.154 2002/05/20 23:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -494,9 +494,9 @@ CopyTo(Relation rel, bool binary, bool oids, FILE *fp,
 		CopySendData(&tmp, sizeof(int32), fp);
 	}
 
-	scandesc = heap_beginscan(rel, 0, QuerySnapshot, 0, NULL);
+	scandesc = heap_beginscan(rel, QuerySnapshot, 0, NULL);
 
-	while (HeapTupleIsValid(tuple = heap_getnext(scandesc, 0)))
+	while ((tuple = heap_getnext(scandesc, ForwardScanDirection)) != NULL)
 	{
 		bool		need_delim = false;
 
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index bb53ad8b3b..d4bc274ba2 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.89 2002/05/17 01:19:17 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.90 2002/05/20 23:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -387,9 +387,9 @@ dropdb(const char *dbname)
 	ScanKeyEntryInitialize(&key, 0, ObjectIdAttributeNumber,
 						   F_OIDEQ, ObjectIdGetDatum(db_id));
 
-	pgdbscan = heap_beginscan(pgdbrel, 0, SnapshotNow, 1, &key);
+	pgdbscan = heap_beginscan(pgdbrel, SnapshotNow, 1, &key);
 
-	tup = heap_getnext(pgdbscan, 0);
+	tup = heap_getnext(pgdbscan, ForwardScanDirection);
 	if (!HeapTupleIsValid(tup))
 	{
 		/*
@@ -463,8 +463,8 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 	rel = heap_openr(DatabaseRelationName, RowExclusiveLock);
 	ScanKeyEntryInitialize(&scankey, 0, Anum_pg_database_datname,
 						   F_NAMEEQ, NameGetDatum(stmt->dbname));
-	scan = heap_beginscan(rel, 0, SnapshotNow, 1, &scankey);
-	tuple = heap_getnext(scan, 0);
+	scan = heap_beginscan(rel, SnapshotNow, 1, &scankey);
+	tuple = heap_getnext(scan, ForwardScanDirection);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "database \"%s\" does not exist", stmt->dbname);
 
@@ -535,9 +535,9 @@ get_db_info(const char *name, Oid *dbIdP, int4 *ownerIdP,
 	ScanKeyEntryInitialize(&scanKey, 0, Anum_pg_database_datname,
 						   F_NAMEEQ, NameGetDatum(name));
 
-	scan = heap_beginscan(relation, 0, SnapshotNow, 1, &scanKey);
+	scan = heap_beginscan(relation, SnapshotNow, 1, &scanKey);
 
-	tuple = heap_getnext(scan, 0);
+	tuple = heap_getnext(scan, ForwardScanDirection);
 
 	gottuple = HeapTupleIsValid(tuple);
 	if (gottuple)
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index e2ae7f0631..ba270838b6 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 1.73 2002/05/12 20:10:02 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.74 2002/05/20 23:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -736,9 +736,9 @@ ReindexDatabase(const char *dbname, bool force, bool all)
 	 * Scan pg_class to build a list of the relations we need to reindex.
 	 */
 	relationRelation = heap_openr(RelationRelationName, AccessShareLock);
-	scan = heap_beginscan(relationRelation, false, SnapshotNow, 0, NULL);
+	scan = heap_beginscan(relationRelation, SnapshotNow, 0, NULL);
 	relcnt = relalc = 0;
-	while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		if (!all)
 		{
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 864ad65eab..f2bbdb0107 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.14 2002/05/17 22:35:12 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.15 2002/05/20 23:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1314,32 +1314,38 @@ update_ri_trigger_args(Oid relid,
 					   bool update_relname)
 {
 	Relation	tgrel;
-	Relation	irel;
 	ScanKeyData skey[1];
-	IndexScanDesc idxtgscan;
-	RetrieveIndexResult idxres;
+	SysScanDesc	trigscan;
+	HeapTuple	tuple;
 	Datum		values[Natts_pg_trigger];
 	char		nulls[Natts_pg_trigger];
 	char		replaces[Natts_pg_trigger];
 
 	tgrel = heap_openr(TriggerRelationName, RowExclusiveLock);
 	if (fk_scan)
-		irel = index_openr(TriggerConstrRelidIndex);
+	{
+		ScanKeyEntryInitialize(&skey[0], 0x0,
+							   Anum_pg_trigger_tgconstrrelid,
+							   F_OIDEQ,
+							   ObjectIdGetDatum(relid));
+		trigscan = systable_beginscan(tgrel, TriggerConstrRelidIndex,
+									  true, SnapshotNow,
+									  1, skey);
+	}
 	else
-		irel = index_openr(TriggerRelidNameIndex);
-
-	ScanKeyEntryInitialize(&skey[0], 0x0,
-						   1,	/* column 1 of index in either case */
-						   F_OIDEQ,
-						   ObjectIdGetDatum(relid));
-	idxtgscan = index_beginscan(irel, false, 1, skey);
+	{
+		ScanKeyEntryInitialize(&skey[0], 0x0,
+							   Anum_pg_trigger_tgrelid,
+							   F_OIDEQ,
+							   ObjectIdGetDatum(relid));
+		trigscan = systable_beginscan(tgrel, TriggerRelidNameIndex,
+									  true, SnapshotNow,
+									  1, skey);
+	}
 
-	while ((idxres = index_getnext(idxtgscan, ForwardScanDirection)) != NULL)
+	while ((tuple = systable_getnext(trigscan)) != NULL)
 	{
-		HeapTupleData tupledata;
-		Buffer		buffer;
-		HeapTuple	tuple;
-		Form_pg_trigger pg_trigger;
+		Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple);
 		bytea	   *val;
 		bytea	   *newtgargs;
 		bool		isnull;
@@ -1352,18 +1358,10 @@ update_ri_trigger_args(Oid relid,
 		const char *arga[RI_MAX_ARGUMENTS];
 		const char *argp;
 
-		tupledata.t_self = idxres->heap_iptr;
-		heap_fetch(tgrel, SnapshotNow, &tupledata, &buffer, idxtgscan);
-		pfree(idxres);
-		if (!tupledata.t_data)
-			continue;
-		tuple = &tupledata;
-		pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple);
 		tg_type = ri_trigger_type(pg_trigger->tgfoid);
 		if (tg_type == RI_TRIGGER_NONE)
 		{
 			/* Not an RI trigger, forget it */
-			ReleaseBuffer(buffer);
 			continue;
 		}
 
@@ -1381,7 +1379,6 @@ update_ri_trigger_args(Oid relid,
 			tgnargs > RI_MAX_ARGUMENTS)
 		{
 			/* This probably shouldn't happen, but ignore busted triggers */
-			ReleaseBuffer(buffer);
 			continue;
 		}
 		argp = (const char *) VARDATA(val);
@@ -1429,7 +1426,6 @@ update_ri_trigger_args(Oid relid,
 		if (!changed)
 		{
 			/* Don't need to update this tuple */
-			ReleaseBuffer(buffer);
 			continue;
 		}
 
@@ -1463,11 +1459,6 @@ update_ri_trigger_args(Oid relid,
 		tuple = heap_modifytuple(tuple, tgrel, values, nulls, replaces);
 
 		/*
-		 * Now we can release hold on original tuple.
-		 */
-		ReleaseBuffer(buffer);
-
-		/*
 		 * Update pg_trigger and its indexes
 		 */
 		simple_heap_update(tgrel, &tuple->t_self, tuple);
@@ -1485,8 +1476,7 @@ update_ri_trigger_args(Oid relid,
 		heap_freetuple(tuple);
 	}
 
-	index_endscan(idxtgscan);
-	index_close(irel);
+	systable_endscan(trigscan);
 
 	heap_close(tgrel, RowExclusiveLock);
 
@@ -1979,9 +1969,9 @@ AlterTableAlterColumnSetNotNull(Oid myrelid,
 	 */
 	tupdesc = RelationGetDescr(rel);
 
-	scan = heap_beginscan(rel, false, SnapshotNow, 0, NULL);
+	scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
 
-	while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Datum 		d;
 		bool		isnull;
@@ -2177,9 +2167,9 @@ drop_default(Oid relid, int16 attnum)
 						   Anum_pg_attrdef_adnum, F_INT2EQ,
 						   Int16GetDatum(attnum));
 
-	scan = heap_beginscan(attrdef_rel, false, SnapshotNow, 2, scankeys);
+	scan = heap_beginscan(attrdef_rel, SnapshotNow, 2, scankeys);
 
-	if (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+	if ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 		simple_heap_delete(attrdef_rel, &tuple->t_self);
 
 	heap_endscan(scan);
@@ -2501,9 +2491,9 @@ AlterTableAddConstraint(Oid myrelid,
 								 * Scan through the rows now, checking the
 								 * expression at each row.
 								 */
-								scan = heap_beginscan(rel, false, SnapshotNow, 0, NULL);
+								scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
 
-								while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+								while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 								{
 									ExecStoreTuple(tuple, slot, InvalidBuffer, false);
 									if (!ExecQual(qual, econtext, true))
@@ -2621,9 +2611,9 @@ AlterTableAddConstraint(Oid myrelid,
 					}
 					trig.tgnargs = count - 1;
 
-					scan = heap_beginscan(rel, false, SnapshotNow, 0, NULL);
+					scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
 
-					while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+					while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 					{
 						/* Make a call to the check function */
 
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index 5398d718b6..c7c3da9dd4 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/src/backend/commands/user.c,v 1.101 2002/05/17 01:19:17 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/user.c,v 1.102 2002/05/20 23:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -140,8 +140,8 @@ write_group_file(Relation urel, Relation grel)
 		elog(ERROR, "write_group_file: unable to write %s: %m", tempname);
 
 	/* read table */
-	scan = heap_beginscan(grel, false, SnapshotSelf, 0, NULL);
-	while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+	scan = heap_beginscan(grel, SnapshotSelf, 0, NULL);
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Datum		datum, grolist_datum;
 		bool		isnull;
@@ -284,8 +284,8 @@ write_user_file(Relation urel)
 		elog(ERROR, "write_password_file: unable to write %s: %m", tempname);
 
 	/* read table */
-	scan = heap_beginscan(urel, false, SnapshotSelf, 0, NULL);
-	while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+	scan = heap_beginscan(urel, SnapshotSelf, 0, NULL);
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Datum		datum;
 		bool		isnull;
@@ -517,10 +517,10 @@ CreateUser(CreateUserStmt *stmt)
 	pg_shadow_rel = heap_openr(ShadowRelationName, ExclusiveLock);
 	pg_shadow_dsc = RelationGetDescr(pg_shadow_rel);
 
-	scan = heap_beginscan(pg_shadow_rel, false, SnapshotNow, 0, NULL);
+	scan = heap_beginscan(pg_shadow_rel, SnapshotNow, 0, NULL);
 	max_id = 99;				/* start auto-assigned ids at 100 */
 	while (!user_exists && !sysid_exists &&
-		   HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+		   (tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Form_pg_shadow shadow_form = (Form_pg_shadow) GETSTRUCT(tuple);
 		int32		this_sysid;
@@ -977,9 +977,9 @@ DropUser(DropUserStmt *stmt)
 							   Anum_pg_database_datdba, F_INT4EQ,
 							   Int32GetDatum(usesysid));
 
-		scan = heap_beginscan(pg_rel, false, SnapshotNow, 1, &scankey);
+		scan = heap_beginscan(pg_rel, SnapshotNow, 1, &scankey);
 
-		if (HeapTupleIsValid(tmp_tuple = heap_getnext(scan, 0)))
+		if ((tmp_tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 		{
 			char	   *dbname;
 
@@ -1012,8 +1012,8 @@ DropUser(DropUserStmt *stmt)
 		 */
 		pg_rel = heap_openr(GroupRelationName, ExclusiveLock);
 		pg_dsc = RelationGetDescr(pg_rel);
-		scan = heap_beginscan(pg_rel, false, SnapshotNow, 0, NULL);
-		while (HeapTupleIsValid(tmp_tuple = heap_getnext(scan, 0)))
+		scan = heap_beginscan(pg_rel, SnapshotNow, 0, NULL);
+		while ((tmp_tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 		{
 			AlterGroupStmt ags;
 
@@ -1148,10 +1148,10 @@ CreateGroup(CreateGroupStmt *stmt)
 	pg_group_rel = heap_openr(GroupRelationName, ExclusiveLock);
 	pg_group_dsc = RelationGetDescr(pg_group_rel);
 
-	scan = heap_beginscan(pg_group_rel, false, SnapshotNow, 0, NULL);
+	scan = heap_beginscan(pg_group_rel, SnapshotNow, 0, NULL);
 	max_id = 99;				/* start auto-assigned ids at 100 */
 	while (!group_exists && !sysid_exists &&
-		   HeapTupleIsValid(tuple = heap_getnext(scan, false)))
+		   (tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Form_pg_group group_form = (Form_pg_group) GETSTRUCT(tuple);
 		int32		this_sysid;
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index eaee990c69..4889e30040 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.224 2002/04/15 23:39:42 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.225 2002/05/20 23:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -350,9 +350,9 @@ getrels(const RangeVar *vacrel, const char *stmttype)
 
 		pgclass = heap_openr(RelationRelationName, AccessShareLock);
 
-		scan = heap_beginscan(pgclass, false, SnapshotNow, 1, &key);
+		scan = heap_beginscan(pgclass, SnapshotNow, 1, &key);
 
-		while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+		while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 		{
 			/* Make a relation list entry for this guy */
 			oldcontext = MemoryContextSwitchTo(vac_context);
@@ -521,9 +521,9 @@ vac_update_dbstats(Oid dbid,
 						   ObjectIdAttributeNumber, F_OIDEQ,
 						   ObjectIdGetDatum(dbid));
 
-	scan = heap_beginscan(relation, 0, SnapshotNow, 1, entry);
+	scan = heap_beginscan(relation, SnapshotNow, 1, entry);
 
-	tuple = heap_getnext(scan, 0);
+	tuple = heap_getnext(scan, ForwardScanDirection);
 
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "database %u does not exist", dbid);
@@ -573,9 +573,9 @@ vac_truncate_clog(TransactionId vacuumXID, TransactionId frozenXID)
 
 	relation = heap_openr(DatabaseRelationName, AccessShareLock);
 
-	scan = heap_beginscan(relation, 0, SnapshotNow, 0, NULL);
+	scan = heap_beginscan(relation, SnapshotNow, 0, NULL);
 
-	while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		Form_pg_database dbform = (Form_pg_database) GETSTRUCT(tuple);