Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1Wfyd3-0007Ib-GC for pgsql-performance@arkaria.postgresql.org; Thu, 01 May 2014 21:34:53 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1Wfyd3-0005JY-0Z for pgsql-performance@arkaria.postgresql.org; Thu, 01 May 2014 21:34:53 +0000 Received: from makus.postgresql.org ([2001:4800:7903:4::125]) by malur.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1Wfyd2-0005JS-6D for pgsql-performance@postgresql.org; Thu, 01 May 2014 21:34:52 +0000 Received: from smtp.01.com ([199.36.142.181]) by makus.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1Wfycz-0005Ix-Ml for pgsql-performance@postgresql.org; Thu, 01 May 2014 21:34:51 +0000 Received: from localhost (localhost [127.0.0.1]) by smtp-out-2.01.com (Postfix) with ESMTP id 59A9040860F; Thu, 1 May 2014 16:34:49 -0500 (CDT) X-Virus-Scanned: amavisd-new at smtp-out-2.01.com Received: from smtp.01.com ([127.0.0.1]) by localhost (smtp-out-2.01.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OIOOw80zOoD5; Thu, 1 May 2014 16:34:49 -0500 (CDT) Received: from smtp.01.com (localhost [127.0.0.1]) by smtp-out-2.01.com (Postfix) with ESMTP id 389434086BF; Thu, 1 May 2014 16:34:49 -0500 (CDT) Received: from localhost (localhost [127.0.0.1]) by smtp-out-2.01.com (Postfix) with ESMTP id 2A83F40860F; Thu, 1 May 2014 16:34:49 -0500 (CDT) X-Virus-Scanned: amavisd-new at smtp-out-2.01.com Received: from smtp.01.com ([127.0.0.1]) by localhost (smtp-out-2.01.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id hOcmMuS14S5P; Thu, 1 May 2014 16:34:49 -0500 (CDT) Received: from [172.47.23.102] (50-0-190-100.dsl.dynamic.sonic.net [50.0.190.100]) by smtp-out-2.01.com (Postfix) with ESMTPSA id B9DCD408647; Thu, 1 May 2014 16:34:48 -0500 (CDT) Message-ID: <5362BDF6.3010400@agliodbs.com> Date: Thu, 01 May 2014 14:34:46 -0700 From: Josh Berkus Organization: PostgreSQL Experts Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Karl Denninger , pgsql-performance@postgresql.org Subject: Re: Revisiting disk layout on ZFS systems References: <535E781A.5030708@denninger.net> In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -1.9 (-) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-performance Precedence: bulk Sender: pgsql-performance-owner@postgresql.org On 04/28/2014 08:47 AM, Karl Denninger wrote: > The odd thing is that I am getting better performance with a 128k record > size on this application than I get with an 8k one! Not only is the > system faster to respond subjectively and can it sustain a higher TPS > load objectively but the I/O busy percentage as measured during > operation is MARKEDLY lower (by nearly an order of magnitude!) Thanks for posting your experience! I'd love it even more if you could post some numbers to go with. Questions: 1) is your database (or the active portion thereof) smaller than RAM? 2) is this a DW workload, where most writes are large writes? -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance