From 10e3acb8e7bd3298ba2b942f86c18f5ba2e142a8 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 13 Nov 2008 17:42:10 +0000 Subject: Prevent synchronous scan during GIN index build, because GIN is optimized for inserting tuples in increasing TID order. It's not clear whether this fully explains Ivan Sergio Borgonovo's complaint, but simple testing confirms that a scan that doesn't start at block 0 can slow GIN build by a factor of three or four. Backpatch to 8.3. Sync scan didn't exist before that. --- src/backend/access/gin/gininsert.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'src/backend/access/gin/gininsert.c') diff --git a/src/backend/access/gin/gininsert.c b/src/backend/access/gin/gininsert.c index 64099cd1e50..6e0a194a694 100644 --- a/src/backend/access/gin/gininsert.c +++ b/src/backend/access/gin/gininsert.c @@ -8,7 +8,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/gin/gininsert.c,v 1.15 2008/09/30 10:52:10 heikki Exp $ + * $PostgreSQL: pgsql/src/backend/access/gin/gininsert.c,v 1.16 2008/11/13 17:42:09 tgl Exp $ *------------------------------------------------------------------------- */ @@ -340,8 +340,11 @@ ginbuild(PG_FUNCTION_ARGS) buildstate.accum.ginstate = &buildstate.ginstate; ginInitBA(&buildstate.accum); - /* do the heap scan */ - reltuples = IndexBuildHeapScan(heap, index, indexInfo, + /* + * Do the heap scan. We disallow sync scan here because dataPlaceToPage + * prefers to receive tuples in TID order. + */ + reltuples = IndexBuildHeapScan(heap, index, indexInfo, false, ginBuildCallback, (void *) &buildstate); /* dump remaining entries to the index */ -- cgit v1.2.3