Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the

free space information is stored in a dedicated FSM relation fork, with each
relation (except for hash indexes; they don't use FSM).

This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any
trace of them from the backend, initdb, and documentation.

Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also
introduce a new variant of the get_raw_page(regclass, int4, int4) function in
contrib/pageinspect that let's you to return pages from any relation fork, and
a new fsm_page_contents() function to inspect the new FSM pages.

src/backend/access/gin/gininsert.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *			$PostgreSQL: pgsql/src/backend/access/gin/gininsert.c,v 1.14 2008/07/11 21:06:29 tgl Exp $
+ *			$PostgreSQL: pgsql/src/backend/access/gin/gininsert.c,v 1.15 2008/09/30 10:52:10 heikki Exp $
  *-------------------------------------------------------------------------
  */
 
@@ -19,6 +19,7 @@
 #include "catalog/index.h"
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
+#include "storage/indexfsm.h"
 #include "utils/memutils.h"
 
 
@@ -283,6 +284,9 @@ ginbuild(PG_FUNCTION_ARGS)
 		elog(ERROR, "index \"%s\" already contains data",
 			 RelationGetRelationName(index));
 
+	/* Initialize FSM */
+	InitIndexFreeSpaceMap(index);
+
 	initGinState(&buildstate.ginstate, index);
 
 	/* initialize the root page */

src/backend/access/gin/ginutil.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *			$PostgreSQL: pgsql/src/backend/access/gin/ginutil.c,v 1.16 2008/07/11 21:06:29 tgl Exp $
+ *			$PostgreSQL: pgsql/src/backend/access/gin/ginutil.c,v 1.17 2008/09/30 10:52:10 heikki Exp $
  *-------------------------------------------------------------------------
  */
 
@@ -19,6 +19,7 @@
 #include "catalog/pg_type.h" 
 #include "storage/bufmgr.h"
 #include "storage/freespace.h"
+#include "storage/indexfsm.h"
 #include "storage/lmgr.h"
 
 void
@@ -151,7 +152,7 @@ GinNewBuffer(Relation index)
 	/* First, try to get a page from FSM */
 	for (;;)
 	{
-		BlockNumber blkno = GetFreeIndexPage(&index->rd_node);
+		BlockNumber blkno = GetFreeIndexPage(index);
 
 		if (blkno == InvalidBlockNumber)
 			break;

src/backend/access/gin/ginvacuum.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *			$PostgreSQL: pgsql/src/backend/access/gin/ginvacuum.c,v 1.21 2008/07/11 21:06:29 tgl Exp $
+ *			$PostgreSQL: pgsql/src/backend/access/gin/ginvacuum.c,v 1.22 2008/09/30 10:52:10 heikki Exp $
  *-------------------------------------------------------------------------
  */
 
@@ -20,6 +20,7 @@
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
 #include "storage/freespace.h"
+#include "storage/indexfsm.h"
 #include "storage/lmgr.h"
 
 typedef struct
@@ -678,10 +679,7 @@ ginvacuumcleanup(PG_FUNCTION_ARGS)
 	bool		needLock;
 	BlockNumber npages,
 				blkno;
-	BlockNumber totFreePages,
-				nFreePages,
-			   *freePages,
-				maxFreePages;
+	BlockNumber totFreePages;
 	BlockNumber lastBlock = GIN_ROOT_BLKNO,
 				lastFilledBlock = GIN_ROOT_BLKNO;
 
@@ -711,12 +709,7 @@ ginvacuumcleanup(PG_FUNCTION_ARGS)
 	if (needLock)
 		UnlockRelationForExtension(index, ExclusiveLock);
 
-	maxFreePages = npages;
-	if (maxFreePages > MaxFSMPages)
-		maxFreePages = MaxFSMPages;
-
-	totFreePages = nFreePages = 0;
-	freePages = (BlockNumber *) palloc(sizeof(BlockNumber) * maxFreePages);
+	totFreePages =  0;
 
 	for (blkno = GIN_ROOT_BLKNO + 1; blkno < npages; blkno++)
 	{
@@ -731,8 +724,7 @@ ginvacuumcleanup(PG_FUNCTION_ARGS)
 
 		if (GinPageIsDeleted(page))
 		{
-			if (nFreePages < maxFreePages)
-				freePages[nFreePages++] = blkno;
+			RecordFreeIndexPage(index, blkno);
 			totFreePages++;
 		}
 		else
@@ -742,25 +734,16 @@ ginvacuumcleanup(PG_FUNCTION_ARGS)
 	}
 	lastBlock = npages - 1;
 
-	if (info->vacuum_full && nFreePages > 0)
+	if (info->vacuum_full && lastBlock > lastFilledBlock)
 	{
 		/* try to truncate index */
-		int			i;
-
-		for (i = 0; i < nFreePages; i++)
-			if (freePages[i] >= lastFilledBlock)
-			{
-				totFreePages = nFreePages = i;
-				break;
-			}
-
-		if (lastBlock > lastFilledBlock)
-			RelationTruncate(index, lastFilledBlock + 1);
+		FreeSpaceMapTruncateRel(index, lastFilledBlock + 1);
+		RelationTruncate(index, lastFilledBlock + 1);
 
 		stats->pages_removed = lastBlock - lastFilledBlock;
+		totFreePages = totFreePages - stats->pages_removed;
 	}
 
-	RecordIndexFreeSpace(&index->rd_node, totFreePages, nFreePages, freePages);
 	stats->pages_free = totFreePages;
 
 	if (needLock)

src/backend/access/gist/gist.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/gist/gist.c,v 1.151 2008/06/12 09:12:29 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/gist/gist.c,v 1.152 2008/09/30 10:52:10 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,6 +19,7 @@
 #include "catalog/index.h"
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
+#include "storage/indexfsm.h"
 #include "utils/memutils.h"
 
 const XLogRecPtr XLogRecPtrForTemp = {1, 1};
@@ -102,6 +103,9 @@ gistbuild(PG_FUNCTION_ARGS)
 		elog(ERROR, "index \"%s\" already contains data",
 			 RelationGetRelationName(index));
 
+	/* Initialize FSM */
+	InitIndexFreeSpaceMap(index);
+
 	/* no locking is needed */
 	initGISTstate(&buildstate.giststate, index);
 

src/backend/access/gist/gistutil.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *			$PostgreSQL: pgsql/src/backend/access/gist/gistutil.c,v 1.30 2008/07/13 20:45:46 tgl Exp $
+ *			$PostgreSQL: pgsql/src/backend/access/gist/gistutil.c,v 1.31 2008/09/30 10:52:10 heikki Exp $
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
@@ -16,6 +16,7 @@
 #include "access/gist_private.h"
 #include "access/reloptions.h"
 #include "storage/freespace.h"
+#include "storage/indexfsm.h"
 #include "storage/lmgr.h"
 #include "storage/bufmgr.h"
 #include "utils/rel.h"
@@ -617,7 +618,7 @@ gistNewBuffer(Relation r)
 	/* First, try to get a page from FSM */
 	for (;;)
 	{
-		BlockNumber blkno = GetFreeIndexPage(&r->rd_node);
+		BlockNumber blkno = GetFreeIndexPage(r);
 
 		if (blkno == InvalidBlockNumber)
 			break;				/* nothing left in FSM */

src/backend/access/gist/gistvacuum.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/gist/gistvacuum.c,v 1.36 2008/06/12 09:12:30 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/gist/gistvacuum.c,v 1.37 2008/09/30 10:52:10 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -20,6 +20,7 @@
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
 #include "storage/freespace.h"
+#include "storage/indexfsm.h"
 #include "storage/lmgr.h"
 #include "utils/memutils.h"
 
@@ -518,10 +519,7 @@ gistvacuumcleanup(PG_FUNCTION_ARGS)
 	Relation	rel = info->index;
 	BlockNumber npages,
 				blkno;
-	BlockNumber totFreePages,
-				nFreePages,
-			   *freePages,
-				maxFreePages;
+	BlockNumber	totFreePages;
 	BlockNumber lastBlock = GIST_ROOT_BLKNO,
 				lastFilledBlock = GIST_ROOT_BLKNO;
 	bool		needLock;
@@ -589,13 +587,7 @@ gistvacuumcleanup(PG_FUNCTION_ARGS)
 	if (needLock)
 		UnlockRelationForExtension(rel, ExclusiveLock);
 
-	maxFreePages = npages;
-	if (maxFreePages > MaxFSMPages)
-		maxFreePages = MaxFSMPages;
-
-	totFreePages = nFreePages = 0;
-	freePages = (BlockNumber *) palloc(sizeof(BlockNumber) * maxFreePages);
-
+	totFreePages = 0;
 	for (blkno = GIST_ROOT_BLKNO + 1; blkno < npages; blkno++)
 	{
 		Buffer		buffer;
@@ -609,9 +601,8 @@ gistvacuumcleanup(PG_FUNCTION_ARGS)
 
 		if (PageIsNew(page) || GistPageIsDeleted(page))
 		{
-			if (nFreePages < maxFreePages)
-				freePages[nFreePages++] = blkno;
 			totFreePages++;
+			RecordFreeIndexPage(rel, blkno);
 		}
 		else
 			lastFilledBlock = blkno;
@@ -619,25 +610,15 @@ gistvacuumcleanup(PG_FUNCTION_ARGS)
 	}
 	lastBlock = npages - 1;
 
-	if (info->vacuum_full && nFreePages > 0)
+	if (info->vacuum_full && lastFilledBlock < lastBlock)
 	{							/* try to truncate index */
-		int			i;
+		FreeSpaceMapTruncateRel(rel, lastFilledBlock + 1);
+		RelationTruncate(rel, lastFilledBlock + 1);
 
-		for (i = 0; i < nFreePages; i++)
-			if (freePages[i] >= lastFilledBlock)
-			{
-				totFreePages = nFreePages = i;
-				break;
-			}
-
-		if (lastBlock > lastFilledBlock)
-			RelationTruncate(rel, lastFilledBlock + 1);
 		stats->std.pages_removed = lastBlock - lastFilledBlock;
+		totFreePages = totFreePages - stats->std.pages_removed;
 	}
 
-	RecordIndexFreeSpace(&rel->rd_node, totFreePages, nFreePages, freePages);
-	pfree(freePages);
-
 	/* return statistics */
 	stats->std.pages_free = totFreePages;
 	if (needLock)

src/backend/access/heap/heapam.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.263 2008/09/11 14:01:09 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.264 2008/09/30 10:52:10 heikki Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -4721,6 +4721,9 @@ heap_sync(Relation rel)
 	/* FlushRelationBuffers will have opened rd_smgr */
 	smgrimmedsync(rel->rd_smgr, MAIN_FORKNUM);
 
+	/* sync FSM as well */
+	smgrimmedsync(rel->rd_smgr, FSM_FORKNUM);
+
 	/* toast heap, if any */
 	if (OidIsValid(rel->rd_rel->reltoastrelid))
 	{
@@ -4729,6 +4732,7 @@ heap_sync(Relation rel)
 		toastrel = heap_open(rel->rd_rel->reltoastrelid, AccessShareLock);
 		FlushRelationBuffers(toastrel);
 		smgrimmedsync(toastrel->rd_smgr, MAIN_FORKNUM);
+		smgrimmedsync(toastrel->rd_smgr, FSM_FORKNUM);
 		heap_close(toastrel, AccessShareLock);
 	}
 }

src/backend/access/heap/hio.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/heap/hio.c,v 1.72 2008/07/13 20:45:47 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/heap/hio.c,v 1.73 2008/09/30 10:52:10 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -163,8 +163,7 @@ RelationGetBufferForTuple(Relation relation, Size len,
 		 * We have no cached target page, so ask the FSM for an initial
 		 * target.
 		 */
-		targetBlock = GetPageWithFreeSpace(&relation->rd_node,
-										   len + saveFreeSpace);
+		targetBlock = GetPageWithFreeSpace(relation, len + saveFreeSpace);
 
 		/*
 		 * If the FSM knows nothing of the rel, try the last page before we
@@ -250,7 +249,7 @@ RelationGetBufferForTuple(Relation relation, Size len,
 		 * Update FSM as to condition of this page, and ask for another page
 		 * to try.
 		 */
-		targetBlock = RecordAndGetPageWithFreeSpace(&relation->rd_node,
+		targetBlock = RecordAndGetPageWithFreeSpace(relation,
 													targetBlock,
 													pageFreeSpace,
 													len + saveFreeSpace);

src/backend/access/nbtree/nbtpage.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtpage.c,v 1.110 2008/07/13 20:45:47 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtpage.c,v 1.111 2008/09/30 10:52:10 heikki Exp $
  *
  *	NOTES
  *	   Postgres btree pages look like ordinary relation pages.	The opaque
@@ -27,6 +27,7 @@
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
 #include "storage/freespace.h"
+#include "storage/indexfsm.h"
 #include "storage/lmgr.h"
 #include "utils/inval.h"
 #include "utils/snapmgr.h"
@@ -501,7 +502,7 @@ _bt_getbuf(Relation rel, BlockNumber blkno, int access)
 		 */
 		for (;;)
 		{
-			blkno = GetFreeIndexPage(&rel->rd_node);
+			blkno = GetFreeIndexPage(rel);
 			if (blkno == InvalidBlockNumber)
 				break;
 			buf = ReadBuffer(rel, blkno);

src/backend/access/nbtree/nbtree.c

@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtree.c,v 1.161 2008/06/19 00:46:03 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtree.c,v 1.162 2008/09/30 10:52:10 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -26,6 +26,7 @@
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
 #include "storage/freespace.h"
+#include "storage/indexfsm.h"
 #include "storage/ipc.h"
 #include "storage/lmgr.h"
 #include "utils/memutils.h"
@@ -56,9 +57,7 @@ typedef struct
 	IndexBulkDeleteCallback callback;
 	void	   *callback_state;
 	BTCycleId	cycleid;
-	BlockNumber *freePages;
-	int			nFreePages;		/* number of entries in freePages[] */
-	int			maxFreePages;	/* allocated size of freePages[] */
+	BlockNumber lastUsedPage;
 	BlockNumber totFreePages;	/* true total # of free pages */
 	MemoryContext pagedelcontext;
 } BTVacState;
@@ -110,6 +109,9 @@ btbuild(PG_FUNCTION_ARGS)
 		elog(ERROR, "index \"%s\" already contains data",
 			 RelationGetRelationName(index));
 
+	/* Initialize FSM */
+	InitIndexFreeSpaceMap(index);
+
 	buildstate.spool = _bt_spoolinit(index, indexInfo->ii_Unique, false);
 
 	/*
@@ -623,9 +625,7 @@ btvacuumscan(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 	vstate.callback = callback;
 	vstate.callback_state = callback_state;
 	vstate.cycleid = cycleid;
-	vstate.freePages = NULL;	/* temporarily */
-	vstate.nFreePages = 0;
-	vstate.maxFreePages = 0;
+	vstate.lastUsedPage = BTREE_METAPAGE;
 	vstate.totFreePages = 0;
 
 	/* Create a temporary memory context to run _bt_pagedel in */
@@ -670,17 +670,6 @@ btvacuumscan(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 		if (needLock)
 			UnlockRelationForExtension(rel, ExclusiveLock);
 
-		/* Allocate freePages after we read num_pages the first time */
-		if (vstate.freePages == NULL)
-		{
-			/* No point in remembering more than MaxFSMPages pages */
-			vstate.maxFreePages = MaxFSMPages;
-			if ((BlockNumber) vstate.maxFreePages > num_pages)
-				vstate.maxFreePages = (int) num_pages;
-			vstate.freePages = (BlockNumber *)
-				palloc(vstate.maxFreePages * sizeof(BlockNumber));
-		}
-
 		/* Quit if we've scanned the whole relation */
 		if (blkno >= num_pages)
 			break;
@@ -697,42 +686,22 @@ btvacuumscan(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 	 * acquiring exclusive lock on the index and then rechecking all the
 	 * pages; doesn't seem worth it.
 	 */
-	if (info->vacuum_full && vstate.nFreePages > 0)
+	if (info->vacuum_full && vstate.lastUsedPage < num_pages - 1)
 	{
-		BlockNumber new_pages = num_pages;
+		BlockNumber new_pages = vstate.lastUsedPage + 1;
 
-		while (vstate.nFreePages > 0 &&
-			   vstate.freePages[vstate.nFreePages - 1] == new_pages - 1)
-		{
-			new_pages--;
-			stats->pages_deleted--;
-			vstate.nFreePages--;
-			vstate.totFreePages = vstate.nFreePages;	/* can't be more */
-		}
-		if (new_pages != num_pages)
-		{
-			/*
-			 * Okay to truncate.
-			 */
-			RelationTruncate(rel, new_pages);
+		/*
+		 * Okay to truncate.
+		 */
+		FreeSpaceMapTruncateRel(rel, new_pages);
+		RelationTruncate(rel, new_pages);
 
-			/* update statistics */
-			stats->pages_removed += num_pages - new_pages;
-
-			num_pages = new_pages;
-		}
+		/* update statistics */
+		stats->pages_removed += num_pages - new_pages;
+		vstate.totFreePages -= (num_pages - new_pages);
+		num_pages = new_pages;
 	}
 
-	/*
-	 * Update the shared Free Space Map with the info we now have about free
-	 * pages in the index, discarding any old info the map may have. We do not
-	 * need to sort the page numbers; they're in order already.
-	 */
-	RecordIndexFreeSpace(&rel->rd_node, vstate.totFreePages,
-						 vstate.nFreePages, vstate.freePages);
-
-	pfree(vstate.freePages);
-
 	MemoryContextDelete(vstate.pagedelcontext);
 
 	/* update statistics */
@@ -788,8 +757,7 @@ restart:
 	/*
 	 * If we are recursing, the only case we want to do anything with is a
 	 * live leaf page having the current vacuum cycle ID.  Any other state
-	 * implies we already saw the page (eg, deleted it as being empty). In
-	 * particular, we don't want to risk adding it to freePages twice.
+	 * implies we already saw the page (eg, deleted it as being empty).
 	 */
 	if (blkno != orig_blkno)
 	{
@@ -803,12 +771,15 @@ restart:
 		}
 	}
 
+	/* If the page is in use, update lastUsedPage */
+	if (!_bt_page_recyclable(page) && vstate->lastUsedPage < blkno)
+		vstate->lastUsedPage = blkno;
+
 	/* Page is valid, see what to do with it */
 	if (_bt_page_recyclable(page))
 	{
 		/* Okay to recycle this page */
-		if (vstate->nFreePages < vstate->maxFreePages)
-			vstate->freePages[vstate->nFreePages++] = blkno;
+		RecordFreeIndexPage(rel, blkno);
 		vstate->totFreePages++;
 		stats->pages_deleted++;
 	}
@@ -944,8 +915,7 @@ restart:
 		 */
 		if (ndel && info->vacuum_full)
 		{
-			if (vstate->nFreePages < vstate->maxFreePages)
-				vstate->freePages[vstate->nFreePages++] = blkno;
+			RecordFreeIndexPage(rel, blkno);
 			vstate->totFreePages++;
 		}
 

src/backend/access/nbtree/nbtsort.c

@@ -52,12 +52,14 @@
  * we log the completed index pages to WAL if and only if WAL archiving is
  * active.
  *
+ * This code isn't concerned about the FSM at all. The caller is responsible
+ * for initializing that.
  *
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtsort.c,v 1.117 2008/08/11 11:05:10 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtsort.c,v 1.118 2008/09/30 10:52:10 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */

src/backend/access/transam/rmgr.c

@@ -3,7 +3,7 @@
  *
  * Resource managers definition
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/rmgr.c,v 1.25 2006/11/05 22:42:07 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/rmgr.c,v 1.26 2008/09/30 10:52:11 heikki Exp $
  */
 #include "postgres.h"
 
@@ -19,6 +19,7 @@
 #include "commands/dbcommands.h"
 #include "commands/sequence.h"
 #include "commands/tablespace.h"
+#include "storage/freespace.h"
 #include "storage/smgr.h"
 
 
@@ -30,7 +31,7 @@ const RmgrData RmgrTable[RM_MAX_ID + 1] = {
 	{"Database", dbase_redo, dbase_desc, NULL, NULL, NULL},
 	{"Tablespace", tblspc_redo, tblspc_desc, NULL, NULL, NULL},
 	{"MultiXact", multixact_redo, multixact_desc, NULL, NULL, NULL},
-	{"Reserved 7", NULL, NULL, NULL, NULL, NULL},
+	{"FreeSpaceMap", fsm_redo, fsm_desc, NULL, NULL, NULL},
 	{"Reserved 8", NULL, NULL, NULL, NULL, NULL},
 	{"Heap2", heap2_redo, heap2_desc, NULL, NULL, NULL},
 	{"Heap", heap_redo, heap_desc, NULL, NULL, NULL},

src/backend/access/transam/xlogutils.c

@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/xlogutils.c,v 1.58 2008/08/11 11:05:10 heikki Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlogutils.c,v 1.59 2008/09/30 10:52:11 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -359,6 +359,7 @@ CreateFakeRelcacheEntry(RelFileNode rnode)
 	rel->rd_lockInfo.lockRelId.relId = rnode.relNode;
 
 	rel->rd_targblock = InvalidBlockNumber;
+	rel->rd_fsm_nblocks_cache = InvalidBlockNumber;
 	rel->rd_smgr = NULL;
 
 	return rel;