Received: from makus.postgresql.org (makus.postgresql.org [98.129.198.125]) by mail.postgresql.org (Postfix) with ESMTP id 45DA31648184 for ; Fri, 30 Mar 2012 11:54:01 -0300 (ADT) Received: from mh1.mail.rice.edu ([128.42.201.20]) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1SDdDF-0002Ec-2u for pgsql-performance@postgresql.org; Fri, 30 Mar 2012 14:54:01 +0000 Received: from mh1.mail.rice.edu (localhost.localdomain [127.0.0.1]) by mh1.mail.rice.edu (Postfix) with ESMTP id 7A8ED290FE9; Fri, 30 Mar 2012 09:53:48 -0500 (CDT) Received: from mh1.mail.rice.edu (localhost.localdomain [127.0.0.1]) by mh1.mail.rice.edu (Postfix) with ESMTP id 67EC2297615; Fri, 30 Mar 2012 09:53:48 -0500 (CDT) X-Virus-Scanned: by amavis-2.6.4 at mh1.mail.rice.edu, auth channel Received: from mh1.mail.rice.edu ([127.0.0.1]) by mh1.mail.rice.edu (mh1.mail.rice.edu [127.0.0.1]) (amavis, port 10026) with ESMTP id kYjDoFlM1Mev; Fri, 30 Mar 2012 09:53:48 -0500 (CDT) X-SMTP-Auth: no X-SMTP-Auth: no Received: from aart.rice.edu (aart.rice.edu [168.7.56.48]) by mh1.mail.rice.edu (Postfix) with ESMTP id 31D93290FE9; Fri, 30 Mar 2012 09:53:48 -0500 (CDT) Received: by aart.rice.edu (Postfix, from userid 18612) id 57E1E1001A6; Fri, 30 Mar 2012 09:53:48 -0500 (CDT) Date: Fri, 30 Mar 2012 09:53:48 -0500 From: "ktm@rice.edu" To: "Campbell, Lance" Cc: "pgsql-performance@postgresql.org" Subject: Re: Tablespaces on a raid configuration Message-ID: <20120330145348.GS2533@aart.rice.edu> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-12-10) X-Pg-Spam-Score: -4.2 (----) X-Archive-Number: 201203/186 X-Sequence-Number: 46636 On Fri, Mar 30, 2012 at 02:45:36PM +0000, Campbell, Lance wrote: > PostgreSQL 9.0.x > When PostgreSQL storage is using a relatively large raid 5 or 6 array is there any value in having your tables distributed across multiple tablespaces if those tablespaces will exists on the same raid array? I understand the value if you were to have the tablespaces on different raid arrays. But what about on the same one? > > > Thanks, > > Lance Campbell > Software Architect > Web Services at Public Affairs > 217-333-0382 > I have seen previous discussions about using different filesystems versus a single filesystem and one advantage that multiple tablespaces have is that an fsync on one table/tablespace would not block or be blocked by an fsync on a different table/tablespace at the OS level. Regards, Ken