postgres.git / summary / log / commit / refs

commit    3c4eec4488fef07675db85e73445f410dac732dd
Author:   Simon Riggs <simon@2ndQuadrant.com>
Date:     Mon Dec 03 18:55:42 2012 +0000

    Avoid holding vmbuffer pin after VACUUM.
    During VACUUM if we pause to perform a cycle
    of index cleanup we drop the vmbuffer pin,
    so we should do the same thing when heap
    scan completes. This avoids holding vmbuffer
    pin across the main index cleanup in VACUUM,
    which could be minutes or hours longer than
    necessary for correctness.
    
    Bug report and suggested fix from Pavan Deolasee


 src/backend/commands/vacuumlazy.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index 0e559720dce..0bba48582f9 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -831,6 +831,15 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
 												  vacrelstats->scanned_pages,
 														 num_tuples);
 
+	/*
+	 * Release any remaining pin on visibility map page.
+	 */
+	if (BufferIsValid(vmbuffer))
+	{
+		ReleaseBuffer(vmbuffer);
+		vmbuffer = InvalidBuffer;
+	}
+
 	/* If any tuples need to be deleted, perform final vacuum cycle */
 	/* XXX put a threshold on min number of tuples here? */
 	if (vacrelstats->num_dead_tuples > 0)
@@ -848,13 +857,6 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
 		vacrelstats->num_index_scans++;
 	}
 
-	/* Release the pin on the visibility map page */
-	if (BufferIsValid(vmbuffer))
-	{
-		ReleaseBuffer(vmbuffer);
-		vmbuffer = InvalidBuffer;
-	}
-
 	/* Do post-vacuum cleanup and statistics update for each index */
 	for (i = 0; i < nindexes; i++)
 		lazy_cleanup_index(Irel[i], indstats[i], vacrelstats);


[parent: e0aad34a6b1a]