Received: from localhost (maia-1.hub.org [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id C601A9FB7C8 for ; Sun, 13 May 2007 06:41:48 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-maia, port 10024) with ESMTP id 05885-01 for ; Sun, 13 May 2007 06:41:45 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.5 Received: from ug-out-1314.google.com (ug-out-1314.google.com [66.249.92.173]) by postgresql.org (Postfix) with ESMTP id A3E2B9FB2C4 for ; Sun, 13 May 2007 06:41:45 -0300 (ADT) Received: by ug-out-1314.google.com with SMTP id k3so825216ugf for ; Sun, 13 May 2007 02:41:44 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding:sender; b=uOo+9lGHB2onIytGZgZIQR+R/opu/FFyKZSvqo2B+tmF1oeXp1fLYrQg+wzjrzJvf2ICnWOPS8FrfHIRC4rh6N+hUqe4iIYeJyxvug4TG887ZayrMxkP1VPYEZkCKuWXAySIfPMot6Vng+JY7gZZlbovGSqyaxZDOA0KB1/BmrY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding:sender; b=ZSvx+/RajAfiV1GB6QCBFEj7YUVoOGHj5MCT5Y9iuvVmnXgmT7JImD8i3AOzDN6PmuwkvIFWAtFzfEhLtN4xU7WvsR47/31naJ7vMiyExh/I+mUSCjELe3kprUkq3+8Ee0q0gcMnb9FznZtp0RcuNuVb43hOUH4cmkt8pVCBACE= Received: by 10.67.116.15 with SMTP id t15mr4279445ugm.1179049304223; Sun, 13 May 2007 02:41:44 -0700 (PDT) Received: from ?192.168.1.33? ( [82.9.23.211]) by mx.google.com with ESMTP id 53sm11311175ugn.2007.05.13.02.41.41; Sun, 13 May 2007 02:41:42 -0700 (PDT) Message-ID: <4646DD4E.4000301@enterprisedb.com> Date: Sun, 13 May 2007 10:41:34 +0100 From: Heikki Linnakangas User-Agent: Icedove 1.5.0.10 (X11/20070329) MIME-Version: 1.0 To: Harald Armin Massa CC: pgsql-performance@postgresql.org Subject: Re: Kernel cache vs shared_buffers References: <00b301c79486$1c54da80$0200a8c0@saturn> <4645CF1D.1030309@enterprisedb.com> <7be3f35d0705130139o218a2a38l6471d6c8aeb1c71f@mail.gmail.com> In-Reply-To: <7be3f35d0705130139o218a2a38l6471d6c8aeb1c71f@mail.gmail.com> 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: 200705/244 X-Sequence-Number: 24634 Harald Armin Massa wrote: >> A common rule of thumb people quote here is to set shared_buffers to 1/4 >> of available RAM, and leave the rest for OS cache. That's probably a >> good configuration to start with. > > And just for the record: This rule of thumb does NOT apply to > PostgreSQL on Windows. My current rule of thumb on Windows: set > shared_buffers to minimum * 2 > Adjust effective_cache_size to the number given as "system cache" > within the task manager. Why? -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com