X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id 0DF369FB527 for ; Fri, 1 Sep 2006 18:35:33 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 36162-01 for ; Fri, 1 Sep 2006 18:35:14 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey- Received: from wr-out-0506.google.com (wr-out-0506.google.com [64.233.184.236]) by postgresql.org (Postfix) with ESMTP id ACD669FB71F for ; Fri, 1 Sep 2006 16:49:45 -0300 (ADT) Received: by wr-out-0506.google.com with SMTP id i21so465817wra for ; Fri, 01 Sep 2006 12:49:44 -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=JAxdjIkfA41GCrreG2Swmr3A+URKhKhcJB5ivOGsb1lpR2SVpMp33igaGiNR3lXIrSiapjSK8h8w9G/O620fg9EHHDlD4g9vAKAJrisQ0pfogMTH7GpyEdqQJWUMONINYGmcJ1I7Uz0AYFI77ajZTbKFvbmW/ma8JB6Qlirye2Y= Received: by 10.65.116.7 with SMTP id t7mr925611qbm; Fri, 01 Sep 2006 12:49:44 -0700 (PDT) Received: by 10.65.137.12 with HTTP; Fri, 1 Sep 2006 12:49:43 -0700 (PDT) Message-ID: Date: Fri, 1 Sep 2006 15:49:43 -0400 From: "Merlin Moncure" To: "Guillaume Cottenceau" Subject: Re: increasing shared buffers: how much should be removed from OS filesystem cache? Cc: pgsql-performance@postgresql.org In-Reply-To: <87veo7a5dn.fsf@meuh.mnc.lan> 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> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.299 tagged_above=0 required=5 tests=AWL, DNS_FROM_RFC_ABUSE, SPF_PASS X-Spam-Level: X-Archive-Number: 200609/8 X-Sequence-Number: 20694 On 01 Sep 2006 19:00:52 +0200, Guillaume Cottenceau wrote: > Hi, > > I've been looking at the results from the pg_statio* tables, to > view the impact of increasing the shared buffers to increase > performance. > 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. merlin