Received: from magus.postgresql.org ([87.238.57.229]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TW42T-0002mq-99 for pgsql-performance@postgresql.org; Wed, 07 Nov 2012 11:43:21 +0000 Received: from smtp-outbound-2.vmware.com ([208.91.2.13]) by magus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TW42P-0006KO-FZ for pgsql-performance@postgresql.org; Wed, 07 Nov 2012 11:43:20 +0000 Received: from sc9-mailhost1.vmware.com (sc9-mailhost1.vmware.com [10.113.161.71]) by smtp-outbound-2.vmware.com (Postfix) with ESMTP id 27B3D28507; Wed, 7 Nov 2012 03:43:14 -0800 (PST) Received: from zcs-prod-mta-2.vmware.com (zcs-prod-mta-2.vmware.com [10.113.163.64]) by sc9-mailhost1.vmware.com (Postfix) with ESMTP id 23447183CC; Wed, 7 Nov 2012 03:43:14 -0800 (PST) Received: from localhost (localhost.localdomain [127.0.0.1]) by zcs-prod-mta-2.vmware.com (Postfix) with ESMTP id 9DBC0E1995; Wed, 7 Nov 2012 03:42:42 -0800 (PST) X-Virus-Scanned: amavisd-new at zcs-prod-mta-2.vmware.com Received: from zcs-prod-mta-2.vmware.com ([127.0.0.1]) by localhost (zcs-prod-mta-2.vmware.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id Inbfpe0YRsbh; Wed, 7 Nov 2012 03:42:42 -0800 (PST) Received: from [10.113.228.11] (unknown [10.113.160.14]) by zcs-prod-mta-2.vmware.com (Postfix) with ESMTPSA id 59069E198B; Wed, 7 Nov 2012 03:42:41 -0800 (PST) Message-ID: <509A494D.10607@vmware.com> Date: Wed, 07 Nov 2012 13:43:09 +0200 From: Heikki Linnakangas Organization: VMware User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.10) Gecko/20121027 Icedove/10.0.10 MIME-Version: 1.0 To: Dong Ye CC: Claudio Freire , Ants Aasma , "pgsql-performance@postgresql.org" Subject: Re: dbt2 performance regresses from 9.1.6 to 9.2.1 References: <03E840D17E263A48A5766AD576E0423A03DF0A266E@exch-mbx-111.vmware.com> <03E840D17E263A48A5766AD576E0423A03DDC5BDE7@exch-mbx-111.vmware.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -7.3 (-------) X-Archive-Number: 201211/82 X-Sequence-Number: 48448 On 05.11.2012 16:32, Claudio Freire wrote: > On Sun, Nov 4, 2012 at 7:23 PM, Dong Ye wrote: >>> You are using prepared statements, this makes me think that this >>> regression might be due to support for parameter specific plans for >>> prepared statements. [1] Can you run the test on both versions without >>> prepared statements and see if the regressions remains. >> >> Without prepare statement, we got 48837.33 avg notpm with 9.1.6 and 43264.54 avg notpm with 9.2.1. >> notps over time shows the slowdown of 9.2.1 is evident during the entire course of the run. >> Their profiles are posted on http://pgsql.privatepaste.com/b770f72967 (9.1.6) and http://pgsql.privatepaste.com/6fa8b7f174 (9.2.1). > > You know... it does look as if 9.2.1 is generating a lot more pressure > into the memory allocator (AllocSetAlloc notably higher). Did you check the access plans of the queries? 9.2 planner might choose a slightly worse plan. Or perhaps index-only scans are hurting performance with the DBT-2 queries. - Heikki