X-Original-To: pgsql-admin-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 22FA69DCAA7; Wed, 1 Feb 2006 14:21:35 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 04074-05; Wed, 1 Feb 2006 14:21:34 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- X-Greylist: from auto-whitelisted by SQLgrey- Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 891389DCAC5; Wed, 1 Feb 2006 14:21:32 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id k11IIV4A003156; Wed, 1 Feb 2006 13:18:32 -0500 (EST) To: Alvaro Herrera cc: Chris Browne , pgsql-admin@postgresql.org, pgsql-hackers@postgresql.org Subject: Re: [HACKERS] autovacuum In-reply-to: <20060201172905.GA7879@surnet.cl> References: <1137992841.28304.48.camel@localhost.localdomain> <5001.71.40.140.99.1138286468.squirrel@mail.tocr.com> <60psm7knlq.fsf@dba2.int.libertyrms.com> <20060201172905.GA7879@surnet.cl> Comments: In-reply-to Alvaro Herrera message dated "Wed, 01 Feb 2006 14:29:05 -0300" Date: Wed, 01 Feb 2006 13:18:31 -0500 Message-ID: <3155.1138817911@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.103 required=5 tests=[AWL=0.103] X-Spam-Score: 0.103 X-Spam-Level: X-Archive-Number: 200602/6 X-Sequence-Number: 20427 Alvaro Herrera writes: > Hmm, yeah, sounds useful. There's one implementation issue to notice > however, and it's that the autovacuum process dies and restarts for each > iteration, so there's no way for it to remember previous state unless > it's saved somewhere permanent, as the stats info is. I think you'd really need to remember the previous oldest XID on a per-table basis to get full traction out of the idea. But weren't we thinking of tracking something isomorphic to this for purposes of minimizing anti-wraparound VACUUMs? regards, tom lane