Reset btpo.xact following recovery of btree delete page. Add btpo_xact

field into WAL record and reset it from there, rather than using
FrozenTransactionId which can lead to some corner case bugs.

Problem report and suggested route to a fix from Heikki, details by me.

diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c
index c0502e5..4aa7599 100644 (file)
--- a/src/backend/access/nbtree/nbtpage.c
+++ b/src/backend/access/nbtree/nbtpage.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/access/nbtree/nbtpage.c,v 1.120 2010/02/26 02:00:34 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/access/nbtree/nbtpage.c,v 1.121 2010/03/19 10:41:21 sriggs Exp $
  *
  *     NOTES
  *        Postgres btree pages look like ordinary relation pages.      The opaque
@@ -1301,6 +1301,7 @@ _bt_pagedel(Relation rel, Buffer buf, BTStack stack)
                xlrec.deadblk = target;
                xlrec.leftblk = leftsib;
                xlrec.rightblk = rightsib;
+               xlrec.btpo_xact = opaque->btpo.xact;
 
                rdata[0].data = (char *) &xlrec;
                rdata[0].len = SizeOfBtreeDeletePage;

diff --git a/src/backend/access/nbtree/nbtxlog.c b/src/backend/access/nbtree/nbtxlog.c
index 07416d5..782778c 100644 (file)
--- a/src/backend/access/nbtree/nbtxlog.c
+++ b/src/backend/access/nbtree/nbtxlog.c
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/access/nbtree/nbtxlog.c,v 1.62 2010/02/26 02:00:34 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/access/nbtree/nbtxlog.c,v 1.63 2010/03/19 10:41:22 sriggs Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -729,7 +729,7 @@ btree_xlog_delete_page(uint8 info, XLogRecPtr lsn, XLogRecord *record)
 
        pageop->btpo_prev = leftsib;
        pageop->btpo_next = rightsib;
-       pageop->btpo.xact = FrozenTransactionId;
+       pageop->btpo.xact = xlrec->btpo_xact;
        pageop->btpo_flags = BTP_DELETED;
        pageop->btpo_cycleid = 0;
 

diff --git a/src/include/access/nbtree.h b/src/include/access/nbtree.h
index 8b7c33e..eb96b2a 100644 (file)
--- a/src/include/access/nbtree.h
+++ b/src/include/access/nbtree.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/nbtree.h,v 1.130 2010/02/26 02:01:21 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/access/nbtree.h,v 1.131 2010/03/19 10:41:22 sriggs Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -375,7 +375,7 @@ typedef struct xl_btree_vacuum
  * identifies the tuple removed from the parent page (note that we remove
  * this tuple's downlink and the *following* tuple's key).     Note we do not
  * store any content for the deleted page --- it is just rewritten as empty
- * during recovery.
+ * during recovery, apart from resetting the btpo.xact.
  */
 typedef struct xl_btree_delete_page
 {
@@ -383,6 +383,7 @@ typedef struct xl_btree_delete_page
        BlockNumber deadblk;            /* child block being deleted */
        BlockNumber leftblk;            /* child block's left sibling, if any */
        BlockNumber rightblk;           /* child block's right sibling */
+       TransactionId btpo_xact;        /* value of btpo.xact for use in recovery */
        /* xl_btree_metadata FOLLOWS IF XLOG_BTREE_DELETE_PAGE_META */
 } xl_btree_delete_page;