Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 3DAF565014E for ; Thu, 6 Nov 2008 15:35:45 -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 27227-05 for ; Thu, 6 Nov 2008 15:35:44 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from gwmta.wicourts.gov (gwmta.wicourts.gov [165.219.244.99]) by mail.postgresql.org (Postfix) with ESMTP id 5DE97650109 for ; Thu, 6 Nov 2008 15:35:43 -0400 (AST) Received: from Courts-MTA by gwmta.wicourts.gov with Novell_GroupWise; Thu, 06 Nov 2008 13:35:41 -0600 Message-Id: <4912F29E.EE98.0025.0@wicourts.gov> X-Mailer: Novell GroupWise Internet Agent 7.0.3 Date: Thu, 06 Nov 2008 13:35:26 -0600 From: "Kevin Grittner" To: Cc: Subject: Re: Create and drop temp table in 8.3.4 References: <4911957A.EE98.0025.0@wicourts.gov> <4911D4DB.EE98.0025.0@wicourts.gov> <4912EAFF.EE98.0025.0@wicourts.gov> <1225999071.1204.14.camel@jd-laptop.pragmaticzealot.org> In-Reply-To: <1225999071.1204.14.camel@jd-laptop.pragmaticzealot.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Archive-Number: 200811/36 X-Sequence-Number: 31767 >>> "Joshua D. Drake" wrote: > On Thu, 2008-11-06 at 13:02 -0600, Kevin Grittner wrote: >> the new kernel >> defaulted to using write barriers, while the old kernel didn't. Since >> we have a BBU RAID controller, we will add nobarrier to the fstab >> entries. This makes file creation and unlink each about 20 times >> faster. > > Woah... which version of the kernel was old and new? old: kgrittn@DBUTL-PG:/var/pgsql/data/test> cat /proc/version Linux version 2.6.5-7.287.3-bigsmp (geeko@buildhost) (gcc version 3.3.3 (SuSE Linux)) #1 SMP Tue Oct 2 07:31:36 UTC 2007 kgrittn@DBUTL-PG:/var/pgsql/data/test> uname -a Linux DBUTL-PG 2.6.5-7.287.3-bigsmp #1 SMP Tue Oct 2 07:31:36 UTC 2007 i686 i686 i386 GNU/Linux kgrittn@DBUTL-PG:/var/pgsql/data/test> cat /etc/SuSE-release SUSE LINUX Enterprise Server 9 (i586) VERSION = 9 PATCHLEVEL = 3 new: kgrittn@SAWYER-PG:~> cat /proc/version Linux version 2.6.16.60-0.27-smp (geeko@buildhost) (gcc version 4.1.2 20070115 (SUSE Linux)) #1 SMP Mon Jul 28 12:55:32 UTC 2008 kgrittn@SAWYER-PG:~> uname -a Linux SAWYER-PG 2.6.16.60-0.27-smp #1 SMP Mon Jul 28 12:55:32 UTC 2008 x86_64 x86_64 x86_64 GNU/Linux kgrittn@SAWYER-PG:~> cat /etc/SuSE-release SUSE Linux Enterprise Server 10 (x86_64) VERSION = 10 PATCHLEVEL = 2 To be clear, file create and unlink speeds are almost the same between the two kernels without write barriers; the difference is that they were in effect by default in the newer kernel. -Kevin