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 5919E11F66EC for ; Sun, 2 Apr 2006 19:30:25 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 74476-03 for ; Sun, 2 Apr 2006 19:30:24 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from davinci.ethosmedia.com (server227.ethosmedia.com [209.128.84.227]) by postgresql.org (Postfix) with ESMTP id 4813E11F65C5 for ; Sun, 2 Apr 2006 19:30:23 -0300 (ADT) X-EthosMedia-Virus-Scanned: no infections found Received: from [63.195.55.98] (account josh@agliodbs.com HELO spooky.sf.agliodbs.com) by davinci.ethosmedia.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 9201005 for pgsql-performance@postgresql.org; Sun, 02 Apr 2006 15:33:22 -0700 From: Josh Berkus Organization: Aglio Database Solutions To: pgsql-performance@postgresql.org Subject: Re: Query using SeqScan instead of IndexScan Date: Sun, 2 Apr 2006 15:30:55 -0700 User-Agent: KMail/1.8.2 References: <2F1712F1-E5E2-455E-A291-06F300A66549@clickspace.com> <200603292118.50033.josh@agliodbs.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200604021530.55251.josh@agliodbs.com> X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.104 required=5 tests=[AWL=0.104] X-Spam-Score: 0.104 X-Spam-Level: X-Archive-Number: 200604/17 X-Sequence-Number: 18101 Brendan, > But just as a follow up question to your #1 suggestion, I have 8 GB > of ram in my production server. You're saying to set the > effective_cache_size then to 5 GB roughly? Somewhere around 655360? > Currently it is set to 65535. Is that something that's OS dependent? > I'm not sure how much memory my server sets aside for disk caching. Yes, about. =C2=A0It's really a judgement call; you're looking for the appr= oximate=20 combined RAM available for disk caching and shared mem. =C2=A0However, this= is=20 just used as a way of estimating the probability that the data you want is= =20 cached in memory, so you're just trying to be order-of-magnitude accurate,= =20 not to-the-MB accurate. =2D-=20 Josh Berkus Aglio Database Solutions San Francisco