Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1UKzCr-0005j4-VY for pgsql-performance@arkaria.postgresql.org; Wed, 27 Mar 2013 22:52:34 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.72) (envelope-from ) id 1UKzCr-0000ZS-GX for pgsql-performance@arkaria.postgresql.org; Wed, 27 Mar 2013 22:52:33 +0000 Received: from makus.postgresql.org ([2001:4800:7903:4::125]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1UKzCq-0000ZL-LY for pgsql-performance@postgresql.org; Wed, 27 Mar 2013 22:52:32 +0000 Received: from outmail149061.authsmtp.co.uk ([62.13.149.61]) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1UKzCi-0004b3-IQ for pgsql-performance@postgresql.org; Wed, 27 Mar 2013 22:52:30 +0000 Received: from mail-c232.authsmtp.com (mail-c232.authsmtp.com [62.13.128.232]) by punt9.authsmtp.com (8.14.2/8.14.2/Kp) with ESMTP id r2RMqEHt041883; Wed, 27 Mar 2013 22:52:14 GMT Received: from [172.47.23.103] (70-36-143-10.dsl.dynamic.sonic.net [70.36.143.10]) (authenticated bits=0) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id r2RMqBXE004997; Wed, 27 Mar 2013 22:52:12 GMT Message-ID: <5153781A.2030704@agliodbs.com> Date: Wed, 27 Mar 2013 15:52:10 -0700 From: Josh Berkus Organization: PostgreSQL Experts Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: "Nicholson, Brad (Toronto, ON, CA)" CC: "pgsql-performance@postgresql.org" Subject: Re: 9.2.3 upgrade reduced pgbench performance by 60% References: <1CD2DD2A-C8C6-41CB-86CB-D44AE5E245CB@marketsworld.com> <5150B4D0.3020902@agliodbs.com> In-Reply-To: X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Server-Quench: f6eabebc-9730-11e2-b10b-0025903375e2 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCdyZgscClZXSx8a IioLCC5HRQ8+YBZL BAkGMA9GIUINWEQL c1AAcR12OUdbHwkA AHYJWV5RUldwWi1y axRSaxtcZklQXgV1 UktWQhwQFmcVQG5p cx4eVhB7cEtEcH52 KxBkCyEJCRYpaE96 QU5JFGxTZ3oyaWBN TUBYdQZdcABJeRoQ aB4dAXkdCgVyBAwf JSoGd2F3Z3MEYDlN TRsEIV9aW0sHAzUx S1gaEj8iG0YFDz0+ NRIhMFsVGk0cek8j eQV5FDoA X-Authentic-SMTP: 61633136333939.1019:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 70.36.143.10/23 X-AuthVirus-Status: No virus detected - but ensure you scan with your own anti-virus system. X-Pg-Spam-Score: -2.6 (--) 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 > > I saw some similar results comparing 9.0 and 9.2 pgbench tests. My tests were on a VM, but on a dedicate host/hardware with no other VM's running on it to minimize variables. I didn't have a lot of time to dig into it, but I do recall seeing more lock contention on updates on the 9.2 instance though. Ah, good point. At that scale, Colin's test is mostly a contention test. There's something there worth investigating, but it's not a realistic use case. Colin, please try your pgbench tests with -s 100. -- 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