Received: from localhost (pluto.hub.org [200.46.204.4]) by postgresql.org (Postfix) with ESMTP id 5F5519FB335 for ; Fri, 3 Nov 2006 10:36:52 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.4]) (amavisd-new, port 10024) with ESMTP id 62959-02 for ; Fri, 3 Nov 2006 10:36:44 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from mail.metronet.co.uk (mail.metronet.co.uk [213.162.97.75]) by postgresql.org (Postfix) with ESMTP id 2CD0F9FB331 for ; Fri, 3 Nov 2006 10:36:50 -0400 (AST) Received: from mainbox.archonet.com (84-51-143-99.archon037.adsl.metronet.co.uk [84.51.143.99]) by smtp.metronet.co.uk (MetroNet Mail) with ESMTP id B31A074197; Fri, 3 Nov 2006 14:36:48 +0000 (GMT) Received: from [192.168.1.17] (client17.office.archonet.com [192.168.1.17]) by mainbox.archonet.com (Postfix) with ESMTP id 83FCD15EAB; Fri, 3 Nov 2006 14:36:48 +0000 (GMT) Message-ID: <454B5461.4030802@archonet.com> Date: Fri, 03 Nov 2006 14:38:25 +0000 From: Richard Huxton User-Agent: Thunderbird 1.5.0.7 (X11/20060918) MIME-Version: 1.0 To: creimer@brturbo.com.br Cc: pgsql-performance@postgresql.org Subject: Re: Context switch storm References: <454B3B75.6@archonet.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200611/48 X-Sequence-Number: 21818 creimer@brturbo.com.br wrote: >> If you can keep your numbers of clients down below the critical >> level, you should find the overall workload is fine. > > We have at about 600 connections. Is this a case to use a connection > pool (pg_pool) system? Possibly - that should help. I'm assuming that most of your queries are very short, so you could probably get that figure down a lot lower. You'll keep the same amount of queries running through the system, just queue them up. > And why this happens only with 8.0 and 8.1 and not with the 7.4? Not sure. Maybe 8.x is making more intensive use of your memory, possibly with a change in your plans. -- Richard Huxton Archonet Ltd