Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1YnTPY-0003sY-M8 for pgsql-performance@arkaria.postgresql.org; Wed, 29 Apr 2015 14:56:28 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1YnTPY-0000iZ-4r for pgsql-performance@arkaria.postgresql.org; Wed, 29 Apr 2015 14:56:28 +0000 Received: from makus.postgresql.org ([2001:4800:1501:1::229]) by malur.postgresql.org with esmtps (TLS1.2:RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1YnTPW-0000iI-Ko for pgsql-performance@postgresql.org; Wed, 29 Apr 2015 14:56:26 +0000 Received: from relay6-d.mail.gandi.net ([2001:4b98:c:538::198]) by makus.postgresql.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.84) (envelope-from ) id 1YnTPP-0006hg-2G for pgsql-performance@postgresql.org; Wed, 29 Apr 2015 14:56:25 +0000 Received: from mfilter29-d.gandi.net (mfilter29-d.gandi.net [217.70.178.160]) by relay6-d.mail.gandi.net (Postfix) with ESMTP id 14D77FB8C6; Wed, 29 Apr 2015 16:56:17 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at mfilter29-d.gandi.net Received: from relay6-d.mail.gandi.net ([217.70.183.198]) by mfilter29-d.gandi.net (mfilter29-d.gandi.net [10.0.15.180]) (amavisd-new, port 10024) with ESMTP id hrGe0zksJezJ; Wed, 29 Apr 2015 16:56:15 +0200 (CEST) X-Originating-IP: 98.27.58.255 Received: from [192.168.10.146] (cpe-98-27-58-255.nc.res.rr.com [98.27.58.255]) (Authenticated sender: adsend@dunslane.net) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id E16164F1869; Wed, 29 Apr 2015 16:56:13 +0200 (CEST) Message-ID: <5540F10C.9030400@dunslane.net> Date: Wed, 29 Apr 2015 10:56:12 -0400 From: Andrew Dunstan User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: "ktm@rice.edu" , "Joshua D. Drake" CC: Andres Freund , Jan Gunnar Dyrset , "pgsql-performance@postgresql.org" Subject: Re: PostgreSQL disk fragmentation causes performance problems on Windows References: <20150429080639.GC14535@awork2.anarazel.de> <20150429080854.GD14535@awork2.anarazel.de> <5540E588.9080507@commandprompt.com> <20150429143543.GQ3510@aart.rice.edu> In-Reply-To: <20150429143543.GQ3510@aart.rice.edu> Content-Type: text/plain; charset=windows-1252; format=flowed 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 04/29/2015 10:35 AM, ktm@rice.edu wrote: > On Wed, Apr 29, 2015 at 07:07:04AM -0700, Joshua D. Drake wrote: >> On 04/29/2015 01:08 AM, Andres Freund wrote: >> >>>> Which OS and filesystem is this done on? Because many halfway modern >>>> systems, like e.g ext4 and xfs, implement this in the background as >>>> 'delayed allocation'. >>> Oh, it's in the subject. Stupid me, sorry for that. I'd consider testing >>> how much better this behaves under a different operating system, as a >>> shorter term relief. >> This is a known issue on the Windows platform. It is part of the >> limitations of that environment. Linux/Solaris/FreeBSD do not suffer >> from this issue in nearly the same manner. >> >> jD >> > You might consider a CLUSTER or VACUUM FULL to re-write the table with > less fragmentation. > Or pg_repack if you can't handle the lockup time that these involve. cheers andrew -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance