X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id C13CB9FB220 for ; Tue, 5 Sep 2006 10:32:13 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 70432-02 for ; Tue, 5 Sep 2006 13:32:03 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey- Received: from nz-out-0102.google.com (nz-out-0102.google.com [64.233.162.195]) by postgresql.org (Postfix) with ESMTP id CAC819FB20B for ; Tue, 5 Sep 2006 10:32:00 -0300 (ADT) Received: by nz-out-0102.google.com with SMTP id 14so1021510nzn for ; Tue, 05 Sep 2006 06:31:59 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=mQzgkK/F35jomoQdCt7j+62RTcca1VrZjdSb4cL9Xb/j1eC/XC1FgG1WJ1xufGZsfyFZjwNT75l7cSDepodBPDQ/5c4ibVPT/fBU0/4iNcvXOPevXkb6s13O8p3Vu90dHNRRER26YdedoUQCLPJQQrI7HRaSggMObg1MGZfUrZk= Received: by 10.65.250.11 with SMTP id c11mr4613697qbs; Tue, 05 Sep 2006 06:31:59 -0700 (PDT) Received: by 10.65.137.12 with HTTP; Tue, 5 Sep 2006 06:31:59 -0700 (PDT) Message-ID: Date: Tue, 5 Sep 2006 09:31:59 -0400 From: "Merlin Moncure" To: "Joshua D. Drake" Subject: Re: increasing shared buffers: how much should be removed Cc: "Dave Cramer" , "Guillaume Cottenceau" , pgsql-performance@postgresql.org In-Reply-To: <44F8CF32.9040606@commandprompt.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <87veo7a5dn.fsf@meuh.mnc.lan> <44F8CF32.9040606@commandprompt.com> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.199 tagged_above=0 required=5 tests=DNS_FROM_RFC_ABUSE, SPF_PASS X-Spam-Level: X-Archive-Number: 200609/29 X-Sequence-Number: 20715 On 9/1/06, Joshua D. Drake wrote: > >> > >> I think 'shared buffers' is one of the most overrated settings from a > >> performance standpoint. however you must ensure there is enough for > >> things the server does besides caching. It used to be a bigger deal > >> than it is in modern versionf of postgresql modern operating systems. > > Previous to 8.1 I would agree with you, but as of 8.1 it is probably the > most underrated. really? what are the relative advantages of raising shared buffers? I was thinking maybe there might be less context switches in high load environments...I'm really curious what you have to say here. merlin