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some rather dubious assumptions in freespace.c and visibilitymap.c about when rd_fsm_nblocks and rd_vm_nblocks can be out of date.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/commands/sequence.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'src/backend/commands/sequence.c') diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c index 09b6732a6e3..d6c6696e2b2 100644 --- a/src/backend/commands/sequence.c +++ b/src/backend/commands/sequence.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.164 2010/01/02 16:57:37 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.165 2010/02/09 21:43:30 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -29,6 +29,7 @@ #include "storage/bufmgr.h" #include "storage/lmgr.h" #include "storage/proc.h" +#include "storage/smgr.h" #include "utils/acl.h" #include "utils/builtins.h" #include "utils/lsyscache.h" @@ -220,7 +221,7 @@ DefineSequence(CreateSeqStmt *seq) sm->magic = SEQ_MAGIC; /* hack: ensure heap_insert will insert on the just-created page */ - rel->rd_targblock = 0; + RelationSetTargetBlock(rel, 0); /* Now form & insert sequence tuple */ tuple = heap_form_tuple(tupDesc, value, null); -- cgit v1.2.3