Restructure smgr API as per recent proposal. smgr no longer depends on

the relcache, and so the notion of 'blind write' is gone.  This should
improve efficiency in bgwriter and background checkpoint processes.
Internal restructuring in md.c to remove the not-very-useful array of
MdfdVec objects --- might as well just use pointers.
Also remove the long-dead 'persistent main memory' storage manager (mm.c),
since it seems quite unlikely to ever get resurrected.

src/backend/commands/copy.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.217 2004/01/28 21:02:39 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.218 2004/02/10 01:55:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,6 +40,7 @@
 #include "parser/parse_coerce.h"
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
+#include "storage/fd.h"
 #include "tcop/pquery.h"
 #include "tcop/tcopprot.h"
 #include "utils/acl.h"

src/backend/commands/dbcommands.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.130 2004/01/07 18:56:25 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.131 2004/02/10 01:55:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -30,6 +30,7 @@
 #include "commands/comment.h"
 #include "commands/dbcommands.h"
 #include "miscadmin.h"
+#include "storage/fd.h"
 #include "storage/freespace.h"
 #include "storage/sinval.h"
 #include "utils/acl.h"

src/backend/commands/tablecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.97 2004/01/28 21:02:39 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.98 2004/02/10 01:55:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1010,7 +1010,7 @@ setRelhassubclassInRelation(Oid relationId, bool relhassubclass)
 	else
 	{
 		/* no need to change tuple, but force relcache rebuild anyway */
-		CacheInvalidateRelcache(relationId);
+		CacheInvalidateRelcacheByTuple(tuple);
 	}
 
 	heap_freetuple(tuple);

src/backend/commands/trigger.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.163 2003/11/29 19:51:47 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.164 2004/02/10 01:55:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -691,7 +691,7 @@ renametrig(Oid relid,
 		 * relcache entries.  (Ideally this should happen
 		 * automatically...)
 		 */
-		CacheInvalidateRelcache(relid);
+		CacheInvalidateRelcache(targetrel);
 	}
 	else
 	{

src/backend/commands/user.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.136 2004/02/02 17:21:07 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.137 2004/02/10 01:55:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -27,6 +27,7 @@
 #include "commands/user.h"
 #include "libpq/crypt.h"
 #include "miscadmin.h"
+#include "storage/fd.h"
 #include "storage/pmsignal.h"
 #include "utils/acl.h"
 #include "utils/array.h"

src/backend/commands/vacuum.c

@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.271 2004/01/07 18:56:25 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.272 2004/02/10 01:55:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2513,7 +2513,9 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 	/* truncate relation, if needed */
 	if (blkno < nblocks)
 	{
-		blkno = smgrtruncate(DEFAULT_SMGR, onerel, blkno);
+		if (onerel->rd_smgr == NULL)
+			onerel->rd_smgr = smgropen(onerel->rd_node);
+		blkno = smgrtruncate(onerel->rd_smgr, blkno);
 		onerel->rd_nblocks = blkno;		/* update relcache immediately */
 		onerel->rd_targblock = InvalidBlockNumber;
 		vacrelstats->rel_pages = blkno; /* set new number of blocks */
@@ -2582,7 +2584,9 @@ vacuum_heap(VRelStats *vacrelstats, Relation onerel, VacPageList vacuum_pages)
 				(errmsg("\"%s\": truncated %u to %u pages",
 						RelationGetRelationName(onerel),
 						vacrelstats->rel_pages, relblocks)));
-		relblocks = smgrtruncate(DEFAULT_SMGR, onerel, relblocks);
+		if (onerel->rd_smgr == NULL)
+			onerel->rd_smgr = smgropen(onerel->rd_node);
+		relblocks = smgrtruncate(onerel->rd_smgr, relblocks);
 		onerel->rd_nblocks = relblocks; /* update relcache immediately */
 		onerel->rd_targblock = InvalidBlockNumber;
 		vacrelstats->rel_pages = relblocks;		/* set new number of

src/backend/commands/vacuumlazy.c

@@ -31,7 +31,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.35 2004/02/06 19:36:17 wieck Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.36 2004/02/10 01:55:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -148,9 +148,8 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt)
 	vac_open_indexes(onerel, &nindexes, &Irel);
 	hasindex = (nindexes > 0);
 
-	/* Turn on vacuum cost accounting */
-	if (VacuumCostNaptime > 0)
-		VacuumCostActive = true;
+	/* Turn vacuum cost accounting on or off */
+	VacuumCostActive = (VacuumCostNaptime > 0);
 	VacuumCostBalance = 0;
 
 	/* Do the vacuuming */
@@ -784,7 +783,9 @@ lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats)
 	/*
 	 * Do the physical truncation.
 	 */
-	new_rel_pages = smgrtruncate(DEFAULT_SMGR, onerel, new_rel_pages);
+	if (onerel->rd_smgr == NULL)
+		onerel->rd_smgr = smgropen(onerel->rd_node);
+	new_rel_pages = smgrtruncate(onerel->rd_smgr, new_rel_pages);
 	onerel->rd_nblocks = new_rel_pages; /* update relcache immediately */
 	onerel->rd_targblock = InvalidBlockNumber;
 	vacrelstats->rel_pages = new_rel_pages;		/* save new number of