Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id A89B864FD33 for ; Thu, 4 Sep 2008 17:01:45 -0300 (ADT) Received: from postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 29319-07 for ; Thu, 4 Sep 2008 17:01:42 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail.gmx.net (mail.gmx.net [213.165.64.20]) by postgresql.org (Postfix) with SMTP id 6411164FCEF for ; Thu, 4 Sep 2008 17:01:42 -0300 (ADT) Received: (qmail invoked by alias); 04 Sep 2008 20:01:37 -0000 Received: from pD9E83BEA.dip.t-dialin.net (EHLO [192.168.2.50]) [217.232.59.234] by mail.gmx.net (mp055) with SMTP; 04 Sep 2008 22:01:37 +0200 X-Authenticated: #7655942 X-Provags-ID: V01U2FsdGVkX1+LEVFntKuLWcAe3ca+k6oWQuVKcFNo5ofNX3vcAB BfEnRgUk/cvA9x Message-ID: <48C03E9D.60508@gmx.net> Date: Thu, 04 Sep 2008 22:01:33 +0200 From: Ulrich User-Agent: Thunderbird 2.0.0.16 (X11/20080724) MIME-Version: 1.0 To: Scott Marlowe CC: pgsql-performance@postgresql.org Subject: Re: More shared_buffers instead of effective_cache_size? References: <48C035E2.3070407@gmx.net> <48C0395C.4000806@gmx.net> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 X-FuHaFi: 0.6899999999999999 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200809/65 X-Sequence-Number: 31378 Scott Marlowe wrote: > On Thu, Sep 4, 2008 at 1:39 PM, Ulrich wrote: > >>> I wouldn't set shared_buffers that high >>> just because things like vacuum and sorts need memory too >>> >> Okay, I understand that vacuum uses memory, but I thought sorts are done in >> work_mem? I am only sorting the result of one query which will never return >> more than 500 rows. >> > > You can probably play with larger shared memory, but I'm betting that > the fact that you're running under a VM is gonna weigh eveything down > a great deal, to the point that you're tuning is going to have minimal > effect. > Hmm... Why do you think so? Is there a reason for it or do other people have problems with virtual servers and databases? I have reserved cpu power and reserved ram (okay, not much, but it is reserved ;-) ), the only thing I dont have is reserved file-cache. -Ulrich