From 758bd2a433d64bed00ca084203b3e5ccfdea4499 Mon Sep 17 00:00:00 2001 From: Simon Riggs Date: Thu, 16 Jun 2011 10:19:10 +0100 Subject: [PATCH] Respect Hot Standby controls while recycling btree index pages. Btree pages were recycled after VACUUM deletes all records on a page and then a subsequent VACUUM occurs after the RecentXmin horizon is reached. Using RecentXmin meant that we did not respond correctly to the user controls provide to avoid Hot Standby conflicts and so spurious conflicts could be generated in some workload combinations. We now reuse pages only when we reach RecentGlobalXmin, which can be much later in the presence of long running queries and is also controlled by vacuum_defer_cleanup_age and hot_standby_feedback. Noah Misch and Simon Riggs --- src/backend/access/nbtree/nbtpage.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c index 58f47e7b64..65354e6d28 100644 --- a/src/backend/access/nbtree/nbtpage.c +++ b/src/backend/access/nbtree/nbtpage.c @@ -677,6 +677,7 @@ bool _bt_page_recyclable(Page page) { BTPageOpaque opaque; + TransactionId cutoff; /* * It's possible to find an all-zeroes page in an index --- for example, a @@ -689,11 +690,18 @@ _bt_page_recyclable(Page page) /* * Otherwise, recycle if deleted and too old to have any processes - * interested in it. + * interested in it. If we are generating records for Hot Standby + * defer page recycling until RecentGlobalXmin to respect user + * controls specified by vacuum_defer_cleanup_age or hot_standby_feedback. */ + if (XLogStandbyInfoActive()) + cutoff = RecentGlobalXmin; + else + cutoff = RecentXmin; + opaque = (BTPageOpaque) PageGetSpecialPointer(page); if (P_ISDELETED(opaque) && - TransactionIdPrecedesOrEquals(opaque->btpo.xact, RecentXmin)) + TransactionIdPrecedesOrEquals(opaque->btpo.xact, cutoff)) return true; return false; } -- 2.11.0