Received: from localhost (maia-4.hub.org [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id D38E19FB853 for ; Tue, 15 May 2007 14:45:16 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 96124-04-3 for ; Tue, 15 May 2007 14:45:12 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from vms040pub.verizon.net (vms040pub.verizon.net [206.46.252.40]) by postgresql.org (Postfix) with ESMTP id 3EBED9FB61F for ; Tue, 15 May 2007 14:45:11 -0300 (ADT) Received: from osgiliath.mathom.us ([72.66.113.156]) by vms040.mailsrvcs.net (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) with ESMTPA id <0JI300HD7FZ1HQT6@vms040.mailsrvcs.net> for pgsql-performance@postgresql.org; Tue, 15 May 2007 12:45:02 -0500 (CDT) Received: from localhost (localhost [127.0.0.1]) by osgiliath.mathom.us (Postfix) with ESMTP id 173EE1F814 for ; Tue, 15 May 2007 13:44:33 -0400 (EDT) Received: from osgiliath.mathom.us ([127.0.0.1]) by localhost (osgiliath.home.mathom.us [127.0.0.1]) (amavisd-new, port 10024) with LMTP id x0HoxgaC9YtD for ; Tue, 15 May 2007 13:44:30 -0400 (EDT) Received: by osgiliath.mathom.us (Postfix, from userid 1000) id 215221F80E; Tue, 15 May 2007 13:44:29 -0400 (EDT) Date: Tue, 15 May 2007 13:44:29 -0400 From: Michael Stone Subject: Re: [doc patch] a slight VACUUM / VACUUM FULL doc improvement proposal In-reply-to: <87lkfqavg9.fsf@meuh.mnc.lan> To: pgsql-performance@postgresql.org Mail-followup-to: pgsql-performance@postgresql.org Message-id: <20070515174427.GG1785@mathom.us> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii; format=flowed Content-disposition: inline X-Virus-Scanned: Debian amavisd-new at mathom.us X-Pgp-Fingerprint: 53 FF 38 00 E7 DD 0A 9C 84 52 84 C5 EE DF 7C 88 References: <87lkfqavg9.fsf@meuh.mnc.lan> User-Agent: Mutt/1.5.13 (2006-08-11) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200705/274 X-Sequence-Number: 24664 On Tue, May 15, 2007 at 06:43:50PM +0200, Guillaume Cottenceau wrote: >patch - basically, I think the documentation under estimates (or >sometimes misses) the benefit of VACUUM FULL for scans, and the >needs of VACUUM FULL if the routine VACUUM hasn't been done >properly since the database was put in production. It's also possible to overestimate the benefit of vacuum full, leading to people vacuum full'ing almost constantly, then complaining about performance due to the associated overhead. I think there have been more people on this list whose performance problems were caused by unnecessary full vacs than by those whose performance problems were caused by insufficient full vacs. Mike Stone