Rethink the way FSM truncation works. Instead of WAL-logging FSM

truncations in FSM code, call FreeSpaceMapTruncateRel from smgr_redo. To
make that cleaner from modularity point of view, move the WAL-logging one
level up to RelationTruncate, and move RelationTruncate and all the
related WAL-logging to new src/backend/catalog/storage.c file. Introduce
new RelationCreateStorage and RelationDropStorage functions that are used
instead of calling smgrcreate/smgrscheduleunlink directly. Move the
pending rel deletion stuff from smgrcreate/smgrscheduleunlink to the new
functions. This leaves smgr.c as a thin wrapper around md.c; all the
transactional stuff is now in storage.c.

This will make it easier to add new forks with similar truncation logic,
like the visibility map.

2 files changed, 8 insertions, 9 deletions

diff --git a/src/include/access/rmgr.h b/src/include/access/rmgr.h
index 6f018f0bee2..44b8a07a3fc 100644
--- a/src/include/access/rmgr.h
+++ b/src/include/access/rmgr.h
@@ -3,7 +3,7 @@
  *
  * Resource managers definition
  *
- * $PostgreSQL: pgsql/src/include/access/rmgr.h,v 1.18 2008/09/30 10:52:13 heikki Exp $
+ * $PostgreSQL: pgsql/src/include/access/rmgr.h,v 1.19 2008/11/19 10:34:52 heikki Exp $
  */
 #ifndef RMGR_H
 #define RMGR_H
@@ -23,7 +23,6 @@ typedef uint8 RmgrId;
 #define RM_DBASE_ID				4
 #define RM_TBLSPC_ID			5
 #define RM_MULTIXACT_ID			6
-#define RM_FREESPACE_ID			7
 #define RM_HEAP2_ID				9
 #define RM_HEAP_ID				10
 #define RM_BTREE_ID				11
diff --git a/src/include/access/xact.h b/src/include/access/xact.h
index c887716e591..b6439bd2945 100644
--- a/src/include/access/xact.h
+++ b/src/include/access/xact.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/xact.h,v 1.95 2008/08/11 11:05:11 heikki Exp $
+ * $PostgreSQL: pgsql/src/include/access/xact.h,v 1.96 2008/11/19 10:34:52 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -88,10 +88,10 @@ typedef void (*SubXactCallback) (SubXactEvent event, SubTransactionId mySubid,
 typedef struct xl_xact_commit
 {
 	TimestampTz xact_time;		/* time of commit */
-	int			nrels;			/* number of RelFileForks */
+	int			nrels;			/* number of RelFileNodes */
 	int			nsubxacts;		/* number of subtransaction XIDs */
-	/* Array of RelFileFork(s) to drop at commit */
-	RelFileFork	xnodes[1];		/* VARIABLE LENGTH ARRAY */
+	/* Array of RelFileNode(s) to drop at commit */
+	RelFileNode	xnodes[1];		/* VARIABLE LENGTH ARRAY */
 	/* ARRAY OF COMMITTED SUBTRANSACTION XIDs FOLLOWS */
 } xl_xact_commit;
 
@@ -100,10 +100,10 @@ typedef struct xl_xact_commit
 typedef struct xl_xact_abort
 {
 	TimestampTz xact_time;		/* time of abort */
-	int			nrels;			/* number of RelFileForks */
+	int			nrels;			/* number of RelFileNodes */
 	int			nsubxacts;		/* number of subtransaction XIDs */
-	/* Array of RelFileFork(s) to drop at abort */
-	RelFileFork	xnodes[1];		/* VARIABLE LENGTH ARRAY */
+	/* Array of RelFileNode(s) to drop at abort */
+	RelFileNode	xnodes[1];		/* VARIABLE LENGTH ARRAY */
 	/* ARRAY OF ABORTED SUBTRANSACTION XIDs FOLLOWS */
 } xl_xact_abort;