Fix contrib/pg_freespacemap's underestimate of the number of pages it

could find in the FSM.  Per report from Dimitri Fontaine and Andrew Gierth.

(Affects only 8.2 and 8.3 since HEAD no longer has MaxFSMPages at all.)
This commit is contained in:
Tom Lane 2009-04-07 18:10:56 +00:00
parent a1fd16a5f6
commit 03baf4dd81

View File

@ -3,7 +3,7 @@
* pg_freespacemap.c
* display some contents of the free space relation and page maps.
*
* $PostgreSQL: pgsql/contrib/pg_freespacemap/pg_freespacemap.c,v 1.9 2006/10/19 18:32:46 tgl Exp $
* $PostgreSQL: pgsql/contrib/pg_freespacemap/pg_freespacemap.c,v 1.9.4.1 2009/04/07 18:10:56 tgl Exp $
*-------------------------------------------------------------------------
*/
#include "postgres.h"
@ -94,6 +94,7 @@ pg_freespacemap_pages(PG_FUNCTION_ARGS)
if (SRF_IS_FIRSTCALL())
{
int i;
int nchunks; /* Size of freespace.c's arena. */
int numPages; /* Max possible no. of pages in map. */
int nPages; /* Mapped pages for a relation. */
@ -102,7 +103,10 @@ pg_freespacemap_pages(PG_FUNCTION_ARGS)
*/
FreeSpaceMap = GetFreeSpaceMap();
numPages = MaxFSMPages;
/* this must match calculation in InitFreeSpaceMap(): */
nchunks = (MaxFSMPages - 1) / CHUNKPAGES + 1;
/* Worst case (lots of indexes) could have this many pages: */
numPages = nchunks * INDEXCHUNKPAGES;
funcctx = SRF_FIRSTCALL_INIT();