From 62656617dbe49cca140f3da588a5e311b3fc35ea Mon Sep 17 00:00:00 2001
From: Simon Riggs <simon@2ndQuadrant.com>
Date: Mon, 3 Dec 2012 18:53:31 +0000
Subject: [PATCH] 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 c9253a9c479..503684936b3 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -949,6 +949,15 @@ 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)
@@ -966,13 +975,6 @@ 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);
--
GitLab