Remove mark/restore support in GIN and GiST indexes.

Per Tom's comment.
Also revome useless GISTScanOpaque->flags field.

src/backend/access/gin/ginget.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *			$PostgreSQL: pgsql/src/backend/access/gin/ginget.c,v 1.19 2008/09/04 11:47:05 teodor Exp $
+ *			$PostgreSQL: pgsql/src/backend/access/gin/ginget.c,v 1.20 2008/10/20 13:39:44 teodor Exp $
  *-------------------------------------------------------------------------
  */
 
@@ -582,54 +582,6 @@ entryGetItem(Relation index, GinScanEntry entry)
 	return entry->isFinished;
 }
 
-/*
- * restart from saved position. Actually it's needed only for
- * partial match. function is called only by ginrestpos()
- */
-void
-ginrestartentry(GinScanEntry entry)
-{
-	ItemPointerData stopItem = entry->curItem;
-	bool savedReduceResult;
-
-	if ( entry->master || entry->partialMatch == NULL )
-		return; /* entry is slave or not a partial match type*/
-
-	if ( entry->isFinished )
-		return; /* entry was finished before ginmarkpos() call */
-
-	if ( ItemPointerGetBlockNumber(&stopItem) == InvalidBlockNumber )
-		return; /* entry  wasn't began before ginmarkpos() call */
-
-	/*
-	 * Reset iterator
-	 */
-	tbm_begin_iterate( entry->partialMatch );
-	entry->partialMatchResult = NULL;
-	entry->offset = 0;
-
-	/*
-	 * Temporary reset reduceResult flag to guarantee refinding
-	 * of curItem
-	 */
-	savedReduceResult = entry->reduceResult;
-	entry->reduceResult = FALSE;
-
-	do
-	{
-		/*
-		 * We can use null instead of index because
-		 * partial match doesn't use it
-		 */
-		if ( entryGetItem( NULL, entry ) == false )
-			elog(ERROR, "cannot refind scan position"); /* must not be here! */
-	} while( compareItemPointers( &stopItem, &entry->curItem ) != 0 );
-
-	Assert( entry->isFinished == FALSE );
-
-	entry->reduceResult = savedReduceResult;
-}
-
 /*
  * Sets key->curItem to new found heap item pointer for one scan key
  * Returns isFinished, ie TRUE means we did NOT get a new item pointer!

src/backend/access/gin/ginscan.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *			$PostgreSQL: pgsql/src/backend/access/gin/ginscan.c,v 1.18 2008/09/04 11:47:05 teodor Exp $
+ *			$PostgreSQL: pgsql/src/backend/access/gin/ginscan.c,v 1.19 2008/10/20 13:39:44 teodor Exp $
  *-------------------------------------------------------------------------
  */
 
@@ -114,7 +114,7 @@ resetScanKeys(GinScanKey keys, uint32 nkeys)
 #endif
 
 static void
-freeScanKeys(GinScanKey keys, uint32 nkeys, bool removeRes)
+freeScanKeys(GinScanKey keys, uint32 nkeys)
 {
 	uint32		i,
 				j;
@@ -130,14 +130,13 @@ freeScanKeys(GinScanKey keys, uint32 nkeys, bool removeRes)
 		{
 			if (key->scanEntry[j].buffer != InvalidBuffer)
 				ReleaseBuffer(key->scanEntry[j].buffer);
-			if (removeRes && key->scanEntry[j].list)
+			if (key->scanEntry[j].list)
 				pfree(key->scanEntry[j].list);
-			if (removeRes && key->scanEntry[j].partialMatch)
+			if (key->scanEntry[j].partialMatch)
 				tbm_free(key->scanEntry[j].partialMatch);
 		}
 
-		if (removeRes)
-			pfree(key->entryRes);
+		pfree(key->entryRes);
 		pfree(key->scanEntry);
 	}
 
@@ -233,11 +232,10 @@ ginrescan(PG_FUNCTION_ARGS)
 	}
 	else
 	{
-		freeScanKeys(so->keys, so->nkeys, TRUE);
-		freeScanKeys(so->markPos, so->nkeys, FALSE);
+		freeScanKeys(so->keys, so->nkeys);
 	}
 
-	so->markPos = so->keys = NULL;
+	so->keys = NULL;
 
 	if (scankey && scan->numberOfKeys > 0)
 	{
@@ -257,8 +255,7 @@ ginendscan(PG_FUNCTION_ARGS)
 
 	if (so != NULL)
 	{
-		freeScanKeys(so->keys, so->nkeys, TRUE);
-		freeScanKeys(so->markPos, so->nkeys, FALSE);
+		freeScanKeys(so->keys, so->nkeys);
 
 		MemoryContextDelete(so->tempCtx);
 
@@ -268,60 +265,16 @@ ginendscan(PG_FUNCTION_ARGS)
 	PG_RETURN_VOID();
 }
 
-static GinScanKey
-copyScanKeys(GinScanKey keys, uint32 nkeys, bool restart)
-{
-	GinScanKey	newkeys;
-	uint32		i,
-				j;
-
-	newkeys = (GinScanKey) palloc(sizeof(GinScanKeyData) * nkeys);
-	memcpy(newkeys, keys, sizeof(GinScanKeyData) * nkeys);
-
-	for (i = 0; i < nkeys; i++)
-	{
-		newkeys[i].scanEntry = (GinScanEntry) palloc(sizeof(GinScanEntryData) * keys[i].nentries);
-		memcpy(newkeys[i].scanEntry, keys[i].scanEntry, sizeof(GinScanEntryData) * keys[i].nentries);
-
-		for (j = 0; j < keys[i].nentries; j++)
-		{
-			if (keys[i].scanEntry[j].buffer != InvalidBuffer)
-				IncrBufferRefCount(keys[i].scanEntry[j].buffer);
-			if (keys[i].scanEntry[j].master)
-			{
-				int			masterN = keys[i].scanEntry[j].master - keys[i].scanEntry;
-
-				newkeys[i].scanEntry[j].master = newkeys[i].scanEntry + masterN;
-			}
-
-			if ( restart )
-				ginrestartentry( &keys[i].scanEntry[j] );
-		}
-	}
-
-	return newkeys;
-}
-
 Datum
 ginmarkpos(PG_FUNCTION_ARGS)
 {
-	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
-	GinScanOpaque so = (GinScanOpaque) scan->opaque;
-
-	freeScanKeys(so->markPos, so->nkeys, FALSE);
-	so->markPos = copyScanKeys(so->keys, so->nkeys, FALSE);
-
+	elog(ERROR, "GIN does not support mark/restore");
 	PG_RETURN_VOID();
 }
 
 Datum
 ginrestrpos(PG_FUNCTION_ARGS)
 {
-	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
-	GinScanOpaque so = (GinScanOpaque) scan->opaque;
-
-	freeScanKeys(so->keys, so->nkeys, FALSE);
-	so->keys = copyScanKeys(so->markPos, so->nkeys, TRUE);
-
+	elog(ERROR, "GIN does not support mark/restore");
 	PG_RETURN_VOID();
 }

src/backend/access/gist/gistget.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/gist/gistget.c,v 1.76 2008/10/17 17:02:21 teodor Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/gist/gistget.c,v 1.77 2008/10/20 13:39:44 teodor Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -494,16 +494,6 @@ gistfindnext(IndexScanDesc scan, OffsetNumber n, ScanDirection dir)
 	 */
 	oldcxt = MemoryContextSwitchTo(so->tempCxt);
 
-	/*
-	 * If we modified the index during the scan, we may have a pointer to a
-	 * ghost tuple, before the scan.  If this is the case, back up one.
-	 */
-	if (so->flags & GS_CURBEFORE)
-	{
-		so->flags &= ~GS_CURBEFORE;
-		n = OffsetNumberPrev(n);
-	}
-
 	while (n >= FirstOffsetNumber && n <= maxoff)
 	{
 		it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));

src/backend/access/gist/gistscan.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/gist/gistscan.c,v 1.72 2008/10/17 17:02:21 teodor Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/gist/gistscan.c,v 1.73 2008/10/20 13:39:44 teodor Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -49,30 +49,21 @@ gistrescan(PG_FUNCTION_ARGS)
 	{
 		/* rescan an existing indexscan --- reset state */
 		gistfreestack(so->stack);
-		gistfreestack(so->markstk);
-		so->stack = so->markstk = NULL;
-		so->flags = 0x0;
+		so->stack = NULL;
 		/* drop pins on buffers -- no locks held */
 		if (BufferIsValid(so->curbuf))
 		{
 			ReleaseBuffer(so->curbuf);
 			so->curbuf = InvalidBuffer;
 		}
-		if (BufferIsValid(so->markbuf))
-		{
-			ReleaseBuffer(so->markbuf);
-			so->markbuf = InvalidBuffer;
-		}
-
 	}
 	else
 	{
 		/* initialize opaque data */
 		so = (GISTScanOpaque) palloc(sizeof(GISTScanOpaqueData));
-		so->stack = so->markstk = NULL;
-		so->flags = 0x0;
+		so->stack = NULL;
 		so->tempCxt = createTempGistContext();
-		so->curbuf = so->markbuf = InvalidBuffer;
+		so->curbuf = InvalidBuffer;
 		so->giststate = (GISTSTATE *) palloc(sizeof(GISTSTATE));
 		initGISTstate(so->giststate, scan->indexRelation);
 
@@ -83,7 +74,6 @@ gistrescan(PG_FUNCTION_ARGS)
 	 * Clear all the pointers.
 	 */
 	ItemPointerSetInvalid(&so->curpos);
-	ItemPointerSetInvalid(&so->markpos);
 	so->nPageData = so->curPageData = 0;
 
 	/* Update scan key, if a new one is given */
@@ -119,108 +109,14 @@ gistrescan(PG_FUNCTION_ARGS)
 Datum
 gistmarkpos(PG_FUNCTION_ARGS)
 {
-	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
-	GISTScanOpaque so;
-	GISTSearchStack *o,
-			   *n,
-			   *tmp;
-
-	so = (GISTScanOpaque) scan->opaque;
-	so->markpos = so->curpos;
-	if (so->flags & GS_CURBEFORE)
-		so->flags |= GS_MRKBEFORE;
-	else
-		so->flags &= ~GS_MRKBEFORE;
-
-	o = NULL;
-	n = so->stack;
-
-	/* copy the parent stack from the current item data */
-	while (n != NULL)
-	{
-		tmp = (GISTSearchStack *) palloc(sizeof(GISTSearchStack));
-		tmp->lsn = n->lsn;
-		tmp->parentlsn = n->parentlsn;
-		tmp->block = n->block;
-		tmp->next = o;
-		o = tmp;
-		n = n->next;
-	}
-
-	gistfreestack(so->markstk);
-	so->markstk = o;
-
-	/* Update markbuf: make sure to bump ref count on curbuf */
-	if (BufferIsValid(so->markbuf))
-	{
-		ReleaseBuffer(so->markbuf);
-		so->markbuf = InvalidBuffer;
-	}
-	if (BufferIsValid(so->curbuf))
-	{
-		IncrBufferRefCount(so->curbuf);
-		so->markbuf = so->curbuf;
-	}
-
-	so->markNPageData = so->nPageData;
-	so->markCurPageData = so->curPageData;
-	if ( so->markNPageData > 0 )
-		memcpy( so->markPageData, so->pageData, sizeof(ItemResult) * so->markNPageData );		
-
+	elog(ERROR, "GiST does not support mark/restore");
 	PG_RETURN_VOID();
 }
 
 Datum
 gistrestrpos(PG_FUNCTION_ARGS)
 {
-	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
-	GISTScanOpaque so;
-	GISTSearchStack *o,
-			   *n,
-			   *tmp;
-
-	so = (GISTScanOpaque) scan->opaque;
-	so->curpos = so->markpos;
-	if (so->flags & GS_MRKBEFORE)
-		so->flags |= GS_CURBEFORE;
-	else
-		so->flags &= ~GS_CURBEFORE;
-
-	o = NULL;
-	n = so->markstk;
-
-	/* copy the parent stack from the current item data */
-	while (n != NULL)
-	{
-		tmp = (GISTSearchStack *) palloc(sizeof(GISTSearchStack));
-		tmp->lsn = n->lsn;
-		tmp->parentlsn = n->parentlsn;
-		tmp->block = n->block;
-		tmp->next = o;
-		o = tmp;
-		n = n->next;
-	}
-
-	gistfreestack(so->stack);
-	so->stack = o;
-
-	/* Update curbuf: be sure to bump ref count on markbuf */
-	if (BufferIsValid(so->curbuf))
-	{
-		ReleaseBuffer(so->curbuf);
-		so->curbuf = InvalidBuffer;
-	}
-	if (BufferIsValid(so->markbuf))
-	{
-		IncrBufferRefCount(so->markbuf);
-		so->curbuf = so->markbuf;
-	}
-
-	so->nPageData = so->markNPageData;
-	so->curPageData = so->markNPageData;
-	if ( so->markNPageData > 0 )
-		memcpy( so->pageData, so->markPageData, sizeof(ItemResult) * so->markNPageData );		
-
+	elog(ERROR, "GiST does not support mark/restore");
 	PG_RETURN_VOID();
 }
 
@@ -235,14 +131,11 @@ gistendscan(PG_FUNCTION_ARGS)
 	if (so != NULL)
 	{
 		gistfreestack(so->stack);
-		gistfreestack(so->markstk);
 		if (so->giststate != NULL)
 			freeGISTstate(so->giststate);
 		/* drop pins on buffers -- we aren't holding any locks */
 		if (BufferIsValid(so->curbuf))
 			ReleaseBuffer(so->curbuf);
-		if (BufferIsValid(so->markbuf))
-			ReleaseBuffer(so->markbuf);
 		MemoryContextDelete(so->tempCxt);
 		pfree(scan->opaque);
 	}

src/include/access/gin.h

@@ -4,7 +4,7 @@
  *
  *	Copyright (c) 2006-2008, PostgreSQL Global Development Group
  *
- *	$PostgreSQL: pgsql/src/include/access/gin.h,v 1.24 2008/07/13 21:50:04 tgl Exp $
+ *	$PostgreSQL: pgsql/src/include/access/gin.h,v 1.25 2008/10/20 13:39:44 teodor Exp $
  *--------------------------------------------------------------------------
  */
 
@@ -426,8 +426,6 @@ typedef struct GinScanOpaqueData
 	uint32		nkeys;
 	bool		isVoidRes;		/* true if ginstate.extractQueryFn guarantees
 								 * that nothing will be found */
-
-	GinScanKey	markPos;
 } GinScanOpaqueData;
 
 typedef GinScanOpaqueData *GinScanOpaque;
@@ -449,7 +447,6 @@ extern PGDLLIMPORT int GinFuzzySearchLimit;
 
 extern Datum gingetbitmap(PG_FUNCTION_ARGS);
 extern Datum gingettuple(PG_FUNCTION_ARGS);
-extern void ginrestartentry(GinScanEntry entry);
 
 /* ginvacuum.c */
 extern Datum ginbulkdelete(PG_FUNCTION_ARGS);

src/include/access/gist_private.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/gist_private.h,v 1.33 2008/10/17 17:02:21 teodor Exp $
+ * $PostgreSQL: pgsql/src/include/access/gist_private.h,v 1.34 2008/10/20 13:39:44 teodor Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -72,21 +72,15 @@ typedef struct GISTScanOpaqueData
 {
 	GISTSearchStack *stack;
 	GISTSearchStack *markstk;
-	uint16		flags;
 	bool        qual_ok;        /* false if qual can never be satisfied */
 	GISTSTATE  *giststate;
 	MemoryContext tempCxt;
 	Buffer		curbuf;
 	ItemPointerData curpos;
-	Buffer		markbuf;
-	ItemPointerData markpos;
 
 	ItemResult		pageData[BLCKSZ/sizeof(IndexTupleData)];
 	OffsetNumber	nPageData;
 	OffsetNumber	curPageData;
-	ItemResult		markPageData[BLCKSZ/sizeof(IndexTupleData)];
-	OffsetNumber	markNPageData;
-	OffsetNumber	markCurPageData;
 } GISTScanOpaqueData;
 
 typedef GISTScanOpaqueData *GISTScanOpaque;
@@ -225,15 +219,6 @@ typedef struct
 	ItemPointerData key;
 } GISTInsertState;
 
-/*
- * When we're doing a scan and updating a tree at the same time, the
- * updates may affect the scan.  We use the flags entry of the scan's
- * opaque space to record our actual position in response to updates
- * that we can't handle simply by adjusting pointers.
- */
-#define GS_CURBEFORE	((uint16) (1 << 0))
-#define GS_MRKBEFORE	((uint16) (1 << 1))
-
 /* root page of a gist index */
 #define GIST_ROOT_BLKNO				0