Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 63B3563223E for ; Tue, 6 Jan 2009 19:33:17 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 79303-01 for ; Tue, 6 Jan 2009 19:33:11 -0400 (AST) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from wf-out-1314.google.com (wf-out-1314.google.com [209.85.200.175]) by mail.postgresql.org (Postfix) with ESMTP id 595FC62E452 for ; Tue, 6 Jan 2009 19:33:11 -0400 (AST) Received: by wf-out-1314.google.com with SMTP id 25so8090193wfc.28 for ; Tue, 06 Jan 2009 15:33:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=y7B3LgO6tBBvClVi0/VuKCf1ZSTTQdIbofEPZSk3yoI=; b=pYrHXxSm8sY588EWH1b8QvsTHyXZttHJ/q926eJJFxyXRvIQZmxnMk+onF8C5l8268 jKHfzHa554nNSgXAZ4nSIk57rn3JoGS9S96617VXrCzMnhUwLmYLMJFJ7lcz4XyOWtbE 63BgGe8oqlJZUOIhgowzCxHyJ1boSUKLdRST8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=MjXqFYskt2CDa06mCCVrrs6D7grFHrx1NWhGITsjgP+3D9Z1b4dqAseC9pE5ZNetf+ IdAu8YPNtgbrbT8B6VUj6AfgzG3v4+vOy1hfBKCe3FHw1YS23ih4xoNYMNjDql936Oew 9DoVEFTW9R70Y3lkh3Kqt54ydsphLYVdTaakU= Received: by 10.142.158.17 with SMTP id g17mr9379905wfe.21.1231284789809; Tue, 06 Jan 2009 15:33:09 -0800 (PST) Received: by 10.143.158.14 with HTTP; Tue, 6 Jan 2009 15:33:09 -0800 (PST) Message-ID: <72dbd3150901061533o5f8601cau389ceaf0ad6840cd@mail.gmail.com> Date: Tue, 6 Jan 2009 15:33:09 -0800 From: "David Rees" To: "Stefano Nichele" Subject: Re: understanding postgres issues/bottlenecks Cc: "Merlin Moncure" , pgsql-performance@postgresql.org In-Reply-To: <4963AACF.2070201@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <49638BE9.2030701@gmail.com> <4963AACF.2070201@gmail.com> 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: 200901/18 X-Sequence-Number: 32297 On Tue, Jan 6, 2009 at 11:02 AM, Stefano Nichele wrote: > BTW, why did you said I/O bound ? Which are the parameters that highlight > that ? Sorry for my ignorance.... In addition to the percentage of time spent in wait as Scott said, you can also see the number of processes which are blocked (b column on the left). Those are the processes which would like to run but are waiting for IO to complete.