Fix oversight in collecting values for cleanup_info records.

vacuum_log_cleanup_info() now generates log records with a valid
latestRemovedXid set in all cases. Also be careful not to zero the
value when we do a round of vacuuming part-way through lazy_scan_heap().
Incidentally, this reduces frequency of conflicts in Hot Standby.

diff --git a/src/backend/access/heap/pruneheap.c b/src/backend/access/heap/pruneheap.c
index 89607f57be39b726e97bff269cc9f2e576fcc407..0fee2845d9f712197d6dda6e888e38bd97fed675 100644 (file)
--- a/src/backend/access/heap/pruneheap.c
+++ b/src/backend/access/heap/pruneheap.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/access/heap/pruneheap.c,v 1.22 2010/02/26 02:00:33 momjian Exp $
+ *   $PostgreSQL: pgsql/src/backend/access/heap/pruneheap.c,v 1.23 2010/04/21 17:20:56 sriggs Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -122,8 +122,10 @@ heap_page_prune_opt(Relation relation, Buffer buffer, TransactionId OldestXmin)
         */
        if (PageIsFull(page) || PageGetHeapFreeSpace(page) < minfree)
        {
+           TransactionId ignore = InvalidTransactionId;    /* return value not needed */
+
            /* OK to prune */
-           (void) heap_page_prune(relation, buffer, OldestXmin, true);
+           (void) heap_page_prune(relation, buffer, OldestXmin, true, &ignore);
        }
 
        /* And release buffer lock */
@@ -145,11 +147,12 @@ heap_page_prune_opt(Relation relation, Buffer buffer, TransactionId OldestXmin)
  * send its own new total to pgstats, and we don't want this delta applied
  * on top of that.)
  *
- * Returns the number of tuples deleted from the page.
+ * Returns the number of tuples deleted from the page and sets
+ * latestRemovedXid.
  */
 int
 heap_page_prune(Relation relation, Buffer buffer, TransactionId OldestXmin,
-               bool report_stats)
+               bool report_stats, TransactionId *latestRemovedXid)
 {
    int         ndeleted = 0;
    Page        page = BufferGetPage(buffer);
@@ -273,6 +276,8 @@ heap_page_prune(Relation relation, Buffer buffer, TransactionId OldestXmin,
    if (report_stats && ndeleted > prstate.ndead)
        pgstat_update_heap_dead_tuples(relation, ndeleted - prstate.ndead);
 
+   *latestRemovedXid = prstate.latestRemovedXid;
+
    /*
     * XXX Should we update the FSM information of this page ?
     *

diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index 1cf1ae3e59379aaafbb4fe8195cd8f1e533e93c9..6e807e3b479e2bbc0b690045c848bc88a1f88e05 100644 (file)
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -29,7 +29,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.132 2010/02/26 02:00:40 momjian Exp $
+ *   $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.133 2010/04/21 17:20:56 sriggs Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -274,6 +274,8 @@ vacuum_log_cleanup_info(Relation rel, LVRelStats *vacrelstats)
    if (rel->rd_istemp || !XLogIsNeeded())
        return;
 
+   Assert(TransactionIdIsValid(vacrelstats->latestRemovedXid));
+
    (void) log_heap_cleanup_info(rel->rd_node, vacrelstats->latestRemovedXid);
 }
 
@@ -395,9 +397,11 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
                                  vacrelstats);
            /* Remove tuples from heap */
            lazy_vacuum_heap(onerel, vacrelstats);
-           /* Forget the now-vacuumed tuples, and press on */
+           /*
+            * Forget the now-vacuumed tuples, and press on, but be careful
+            * not to reset latestRemovedXid since we want that value to be valid.
+            */
            vacrelstats->num_dead_tuples = 0;
-           vacrelstats->latestRemovedXid = InvalidTransactionId;
            vacrelstats->num_index_scans++;
        }
 
@@ -484,8 +488,8 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
         *
         * We count tuples removed by the pruning step as removed by VACUUM.
         */
-       tups_vacuumed += heap_page_prune(onerel, buf, OldestXmin, false);
-
+       tups_vacuumed += heap_page_prune(onerel, buf, OldestXmin, false,
+                                                   &vacrelstats->latestRemovedXid);
        /*
         * Now scan the page to collect vacuumable items and check for tuples
         * requiring freezing.
@@ -676,9 +680,12 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
        {
            /* Remove tuples from heap */
            lazy_vacuum_page(onerel, blkno, buf, 0, vacrelstats);
-           /* Forget the now-vacuumed tuples, and press on */
+           /*
+            * Forget the now-vacuumed tuples, and press on, but be careful
+            * not to reset latestRemovedXid since we want that value to be valid.
+            */
+           Assert(TransactionIdIsValid(vacrelstats->latestRemovedXid));
            vacrelstats->num_dead_tuples = 0;
-           vacrelstats->latestRemovedXid = InvalidTransactionId;
            vacuumed_pages++;
        }
 

diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 1f26b376f5c4d0b4afad0b0a7989746e84974721..521f9588fec27b83659ea934ad69f95ad04c3bee 100644 (file)
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.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/heapam.h,v 1.148 2010/02/26 02:01:20 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/access/heapam.h,v 1.149 2010/04/21 17:20:56 sriggs Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -144,7 +144,7 @@ extern void heap_page_prune_opt(Relation relation, Buffer buffer,
                    TransactionId OldestXmin);
 extern int heap_page_prune(Relation relation, Buffer buffer,
                TransactionId OldestXmin,
-               bool report_stats);
+               bool report_stats, TransactionId *latestRemovedXid);
 extern void heap_page_prune_execute(Buffer buffer,
                        OffsetNumber *redirected, int nredirected,
                        OffsetNumber *nowdead, int ndead,