From cbe9d6beb4ae1cb20c08cab29b534be4923b6768 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 9 Feb 2010 21:43:30 +0000 Subject: Fix up rickety handling of relation-truncation interlocks. Move rd_targblock, rd_fsm_nblocks, and rd_vm_nblocks from relcache to the smgr relation entries, so that they will get reset to InvalidBlockNumber whenever an smgr-level flush happens. Because we now send smgr invalidation messages immediately (not at end of transaction) when a relation truncation occurs, this ensures that other backends will reset their values before they next access the relation. We no longer need the unreliable assumption that a VACUUM that's doing a truncation will hold its AccessExclusive lock until commit --- in fact, we can intentionally release that lock as soon as we've completed the truncation. This patch therefore reverts (most of) Alvaro's patch of 2009-11-10, as well as my marginal hacking on it yesterday. We can also get rid of assorted no-longer-needed relcache flushes, which are far more expensive than an smgr flush because they kill a lot more state. In passing this patch fixes smgr_redo's failure to perform visibility-map truncation, and cleans up some rather dubious assumptions in freespace.c and visibilitymap.c about when rd_fsm_nblocks and rd_vm_nblocks can be out of date. --- src/backend/access/transam/xlogutils.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'src/backend/access/transam/xlogutils.c') diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c index 6e1ad771cd2..af6a0d29e80 100644 --- a/src/backend/access/transam/xlogutils.c +++ b/src/backend/access/transam/xlogutils.c @@ -11,7 +11,7 @@ * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/backend/access/transam/xlogutils.c,v 1.69 2010/01/02 16:57:35 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/access/transam/xlogutils.c,v 1.70 2010/02/09 21:43:29 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -393,9 +393,6 @@ CreateFakeRelcacheEntry(RelFileNode rnode) rel->rd_lockInfo.lockRelId.dbId = rnode.dbNode; rel->rd_lockInfo.lockRelId.relId = rnode.relNode; - rel->rd_targblock = InvalidBlockNumber; - rel->rd_fsm_nblocks = InvalidBlockNumber; - rel->rd_vm_nblocks = InvalidBlockNumber; rel->rd_smgr = NULL; return rel; -- cgit v1.2.3