X-Original-To: pgsql-sql-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 46FFD9DCD23 for ; Mon, 19 Dec 2005 00:29:21 -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 95504-04 for ; Mon, 19 Dec 2005 00:29:19 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from alvh.no-ip.org (201-220-123-7.bk10-dsl.surnet.cl [201.220.123.7]) by postgresql.org (Postfix) with ESMTP id 86B8A9DCD0B for ; Mon, 19 Dec 2005 00:29:17 -0400 (AST) Received: by alvh.no-ip.org (Postfix, from userid 1000) id 4C125C348F2; Mon, 19 Dec 2005 01:29:36 -0300 (CLST) Date: Mon, 19 Dec 2005 01:29:36 -0300 From: Alvaro Herrera To: Tom Lane Cc: Martin Marques , frank church , pgsql-sql@postgresql.org Subject: Re: Does VACUUM reorder tables on clustered indices Message-ID: <20051219042935.GA5692@surnet.cl> Mail-Followup-To: Tom Lane , Martin Marques , frank church , pgsql-sql@postgresql.org References: <1134940325.43a5d0a5a882e@webmail.adontendev.net> <20051218220139.GA1651@surnet.cl> <13769.1134961702@sss.pgh.pa.us> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <13769.1134961702@sss.pgh.pa.us> User-Agent: Mutt/1.5.11 X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=1.583 required=5 tests=[AWL=-0.336, DNS_FROM_RFC_ABUSE=0.479, DNS_FROM_RFC_POST=1.44] X-Spam-Score: 1.583 X-Spam-Level: * X-Archive-Number: 200512/153 X-Sequence-Number: 23695 Tom Lane escribió: > Alvaro Herrera writes: > > Note that while reordering, CLUSTER also gets rid of dead tuples, so if > > you cluster you don't need to vacuum. > > Just for the record, that behavior is seriously broken: it violates > MVCC if any of the deleted tuples are still visible to anyone else. Well, FWIW, the fact that the CLUSTER command exists at all is broken IMHO ... but meanwhile, are you suggesting that CLUSTER should be fixed to retain tuples that are visible to running transactions? -- Alvaro Herrera http://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support