X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 48CD39DC86A for ; Tue, 17 Jan 2006 10:33:19 -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 35034-08 for ; Tue, 17 Jan 2006 10:33:23 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from floppy.pyrenet.fr (news.pyrenet.fr [194.116.145.2]) by postgresql.org (Postfix) with ESMTP id BECF29DC81E for ; Tue, 17 Jan 2006 10:33:16 -0400 (AST) Received: by floppy.pyrenet.fr (Postfix, from userid 106) id 8347630F0A; Tue, 17 Jan 2006 15:33:20 +0100 (MET) From: Michael Riess X-Newsgroups: pgsql.performance Subject: Re: Autovacuum / full vacuum Date: Tue, 17 Jan 2006 15:33:18 +0100 Organization: Hub.Org Networking Services Lines: 23 Message-ID: References: <43CCC711.504@familyhealth.com.au> <43CCFA7E.1060307@zeut.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@news.hub.org User-Agent: Thunderbird 1.5 (Windows/20051201) In-Reply-To: <43CCFA7E.1060307@zeut.net> To: pgsql-performance@postgresql.org X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.06 required=5 tests=[AWL=0.060] X-Spam-Score: 0.06 X-Spam-Level: X-Archive-Number: 200601/232 X-Sequence-Number: 16710 Hi, yes, some heavily used tables contain approx. 90% free space after a week. I'll try to increase FSM even more, but I think that I will still have to run a full vacuum every week. Prior to 8.1 I was using 7.4 and ran a full vacuum every day, so the autovacuum has helped a lot. But actually I never understood why the database system slows down at all when there is much unused space in the files. Are the unused pages cached by the system, or is there another reason for the impact on the performance? Mike > Have you measured to see if things are truly > faster after a VACUUM FULL? > > Matt > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend >