Reimplement free-space-map management as per recent discussions.

Adjustable threshold is gone in favor of keeping track of total requested
page storage and doling out proportional fractions to each relation
(with a minimum amount per relation, and some quantization of the results
to avoid thrashing with small changes in page counts).  Provide special-
case code for indexes so as not to waste space storing useless page
free space counts.  Restructure internal data storage to be a flat array
instead of list-of-chunks; this may cost a little more work in data
copying when reorganizing, but allows binary search to be used during
lookup_fsm_page_entry().

1 files changed, 15 insertions, 7 deletions

diff --git a/src/include/storage/freespace.h b/src/include/storage/freespace.h
index 428898bdac..05cf77d761 100644
--- a/src/include/storage/freespace.h
+++ b/src/include/storage/freespace.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: freespace.h,v 1.8 2002/09/20 19:56:01 tgl Exp $
+ * $Id: freespace.h,v 1.9 2003/03/04 21:51:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -28,6 +28,7 @@ typedef struct PageFreeSpaceInfo
 } PageFreeSpaceInfo;
 
 
+/* GUC variables */
 extern int	MaxFSMRelations;
 extern int	MaxFSMPages;
 
@@ -39,19 +40,26 @@ extern void InitFreeSpaceMap(void);
 extern int	FreeSpaceShmemSize(void);
 
 extern BlockNumber GetPageWithFreeSpace(RelFileNode *rel, Size spaceNeeded);
-extern void RecordFreeSpace(RelFileNode *rel, BlockNumber page,
-				Size spaceAvail);
 extern BlockNumber RecordAndGetPageWithFreeSpace(RelFileNode *rel,
 							  BlockNumber oldPage,
 							  Size oldSpaceAvail,
 							  Size spaceNeeded);
-extern void MultiRecordFreeSpace(RelFileNode *rel,
-					 BlockNumber minPage,
-					 int nPages,
-					 PageFreeSpaceInfo *pageSpaces);
+extern Size GetAvgFSMRequestSize(RelFileNode *rel);
+extern void RecordRelationFreeSpace(RelFileNode *rel,
+									int nPages,
+									PageFreeSpaceInfo *pageSpaces);
+
+extern BlockNumber GetFreeIndexPage(RelFileNode *rel);
+extern void RecordIndexFreeSpace(RelFileNode *rel,
+								 int nPages,
+								 BlockNumber *pages);
+
+extern void FreeSpaceMapTruncateRel(RelFileNode *rel, BlockNumber nblocks);
 extern void FreeSpaceMapForgetRel(RelFileNode *rel);
 extern void FreeSpaceMapForgetDatabase(Oid dbid);
 
+extern void PrintFreeSpaceMapStatistics(int elevel);
+
 #ifdef FREESPACE_DEBUG
 extern void DumpFreeSpace(void);
 #endif