Received: from localhost (maia-5.hub.org [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id 254C29FB478 for ; Thu, 25 Jan 2007 09:47:14 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-new, port 10024) with ESMTP id 10210-08 for ; Thu, 25 Jan 2007 09:47:00 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from locust.cns.vt.edu (locust.cns.vt.edu [198.82.169.14]) by postgresql.org (Postfix) with ESMTP id 41F1F9FA4F7 for ; Thu, 25 Jan 2007 09:47:05 -0400 (AST) Received: by locust.cns.vt.edu (Postfix, from userid 986) id C83BB118A24; Thu, 25 Jan 2007 08:47:03 -0500 (EST) Date: Thu, 25 Jan 2007 08:47:03 -0500 From: Ray Stell To: Galy Lee Cc: pgsql-performance@postgresql.org, jim@nasby.net Subject: Re: how to plan for vacuum? Message-ID: <20070125134703.GA7869@cns.vt.edu> References: <45B6F0A8.1050705@oss.ntt.co.jp> <20070125033917.GD64372@nasby.net> <45B88680.4040500@oss.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45B88680.4040500@oss.ntt.co.jp> User-Agent: Mutt/1.5.11 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200701/369 X-Sequence-Number: 22970 On Thu, Jan 25, 2007 at 07:29:20PM +0900, Galy Lee wrote: > so what is the principle to set them? > - keep dead space lower than some disk limit > - or keep the garbage rate lower than fillfactor > or any other general principle? How do you measure "dead space" and "garbage rate?" I'm a newbe, I don't even know what these terms mean, but if I can measure them, perhaps it will gel, and really if you can't measure the effect of a setting change, what have you got? I would hope any discussion on autovac parms would include some metric evaluation techniques. Thanks.