From: Tom Lane <tgl@sss.pgh.pa.us>
To: Chris Browne <cbbrowne@acm.org>
Cc: pgsql-performance@postgresql.org
Subject: Re: Autovacuum / full vacuum
Date: Tue, 17 Jan 2006 14:32:52 -0500
Message-ID: <20592.1137526372@sss.pgh.pa.us> (raw)
In-Reply-To: <604q42elzl.fsf@dba2.int.libertyrms.com>
References: <dqigaf$1b98$1@news.hub.org>
<20060117145649.GE21092@phlogiston.dyndns.org>
<608xteerfh.fsf@dba2.int.libertyrms.com>
<20060117173046.GA4296@surnet.cl>
<604q42elzl.fsf@dba2.int.libertyrms.com>
Chris Browne <cbbrowne@acm.org> writes:
> alvherre@alvh.no-ip.org (Alvaro Herrera) writes:
>> Even a database-wide vacuum does not take locks on more than one table.
>> The table locks are acquired and released one by one, as the operation
>> proceeds.
> Has that changed recently? I have always seen "vacuumdb" or SQL
> "VACUUM" (without table specifications) running as one long
> transaction which doesn't release the locks that it is granted until
> the end of the transaction.
You sure? It's not supposed to, and watching a database-wide vacuum
with "select * from pg_locks" doesn't look to me like it ever has locks
on more than one table (plus the table's indexes and toast table).
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, cbbrowne@acm.org
Subject: Re: Autovacuum / full vacuum
In-Reply-To: <20592.1137526372@sss.pgh.pa.us>
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