diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2012-02-21 15:04:01 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2012-02-21 15:04:01 -0500 |
| commit | 2c293f25494f2d465bcff49d7aab6ec06a40e436 (patch) | |
| tree | 0bc003ffc19c5a9576fb8a4c9ee61fb398e0f97a /src/backend/access/nbtree/nbtpage.c | |
| parent | f3ad4ca00e1f63357751d855a9150d3ba404a2b2 (diff) | |
Don't clear btpo_cycleid during _bt_vacuum_one_page.
When "vacuuming" a single btree page by removing LP_DEAD tuples, we are not
actually within a vacuum operation, but rather in an ordinary insertion
process that could well be running concurrently with a vacuum. So clearing
the cycleid is incorrect, and could cause the concurrent vacuum to miss
removing tuples that it needs to remove. This is a longstanding bug
introduced by commit e6284649b9e30372b3990107a082bc7520325676 of
2006-07-25. I believe it explains Maxim Boguk's recent report of index
corruption, and probably some other previously unexplained reports.
In 9.0 and up this is a one-line fix; before that we need to introduce a
flag to tell _bt_delitems what to do.
Diffstat (limited to 'src/backend/access/nbtree/nbtpage.c')
| -rw-r--r-- | src/backend/access/nbtree/nbtpage.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c index d1a49633936..a89e3ba84f4 100644 --- a/src/backend/access/nbtree/nbtpage.c +++ b/src/backend/access/nbtree/nbtpage.c @@ -650,7 +650,8 @@ _bt_page_recyclable(Page page) */ void _bt_delitems(Relation rel, Buffer buf, - OffsetNumber *itemnos, int nitems) + OffsetNumber *itemnos, int nitems, + bool inVacuum) { Page page = BufferGetPage(buf); BTPageOpaque opaque; @@ -662,11 +663,12 @@ _bt_delitems(Relation rel, Buffer buf, PageIndexMultiDelete(page, itemnos, nitems); /* - * We can clear the vacuum cycle ID since this page has certainly been - * processed by the current vacuum scan. + * If this is within VACUUM, we can clear the vacuum cycle ID since this + * page has certainly been processed by the current vacuum scan. */ opaque = (BTPageOpaque) PageGetSpecialPointer(page); - opaque->btpo_cycleid = 0; + if (inVacuum) + opaque->btpo_cycleid = 0; /* * Mark the page as not containing any LP_DEAD items. This is not |