X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 45E149FA43B for ; Thu, 14 Sep 2006 03:55:27 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 70865-07 for ; Thu, 14 Sep 2006 06:55:23 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey- Received: from web35806.mail.mud.yahoo.com (web35806.mail.mud.yahoo.com [66.163.179.175]) by postgresql.org (Postfix) with SMTP id 9934E9FA36A for ; Thu, 14 Sep 2006 03:55:23 -0300 (ADT) Received: (qmail 23043 invoked by uid 60001); 14 Sep 2006 06:55:22 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=CPmsWlSMula707oy84mTLUzejAJ1mL8wJeGBb2URsCneJLWHmRBScsHBzrl2k6ZtrK28JKH9Cva9EmLB+UD4GJaFCMk926e6EwzeU33PDU+DPRKn0aln4FesPe1T0hH7jsRvUPcuv+LIrNlkn4mEyVHKPBJmhkoFQN28oVs/id8= ; Message-ID: <20060914065522.23041.qmail@web35806.mail.mud.yahoo.com> Received: from [194.29.47.173] by web35806.mail.mud.yahoo.com via HTTP; Wed, 13 Sep 2006 23:55:22 PDT Date: Wed, 13 Sep 2006 23:55:22 -0700 (PDT) From: yoav x Subject: Re: sql-bench To: pgsql-performance@postgresql.org In-Reply-To: <12097.1158161568@sss.pgh.pa.us> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=3.355 tagged_above=0 required=5 tests=DNS_FROM_RFC_ABUSE, DNS_FROM_RFC_POST, DNS_FROM_RFC_WHOIS X-Spam-Level: *** X-Archive-Number: 200609/145 X-Sequence-Number: 20831 You can use the test with InnoDB by giving the --create-options=engine=innodb option in the command line. Even with InnoDB, in some specific tests PG looks very bad compared to InnoDB. --- Tom Lane wrote: > yoav x writes: > > Are there any tuning parameters that can be changed to speed these > > queries? Or are these queries especially tuned to show MySQL's > > stgrenths? > > The latter. I've ranted about this before --- there are both obvious > and subtle biases in that benchmark. The last time I spent any time > with it, I ended up testing with these nondefault settings: > > shared_buffers = 10000 > work_mem = 100000 > maintenance_work_mem = 100000 > fsync = false > checkpoint_segments = 30 > max_locks_per_transaction = 128 > > (fsync = false is pretty bogus for production purposes, but if you're > comparing to mysql using myisam tables, I think it's a reasonably fair > basis for comparison, as myisam is certainly not crash-safe. It'd be > interesting to see what mysql's performance looks like on this test > using innodb tables, which should be compared against fsync = true > ... but I don't know how to change it to get all the tables to be > innodb.) > > Also, on some of the tests it makes a material difference whether you > are using C locale or some other one --- C is faster. And make sure you > have a recent version of DBD::Pg --- a year or two back I recall seeing > the perl test program eating more CPU than the backend in some of these > tests, because of inefficiencies in DBD::Pg. > > IIRC, with these settings PG 8.0 seemed to be about half the speed of > mysql 5.0 w/myisam, which is probably somewhere in the ballpark of the > truth for tests of this nature, ie, single query stream of fairly simple > queries. If you try concurrent-update scenarios or something that > stresses planning ability you may arrive at different results though. > I have not retested with more recent versions. > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 1: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to majordomo@postgresql.org so that your > message can get through to the mailing list cleanly > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com