Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id 938B0B5DC1E for ; Fri, 15 Jul 2011 15:46:24 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.29]) (amavisd-maia, port 10024) with ESMTP id 13581-05 for ; Fri, 15 Jul 2011 18:46:18 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from smtp-4.01.com (smtp-4.01.com [38.102.63.183]) by mail.postgresql.org (Postfix) with ESMTP id 50323B5DBF4 for ; Fri, 15 Jul 2011 15:46:18 -0300 (ADT) Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp-4.01.com (Postfix) with ESMTP id E9A503BC951 for ; Fri, 15 Jul 2011 13:46:17 -0500 (CDT) Received: from smtp-4.01.com ([127.0.0.1]) by localhost (smtp-4.01.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id gLw7scr8BsIO for ; Fri, 15 Jul 2011 13:46:17 -0500 (CDT) Received: by smtp-4.01.com (Postfix, from userid 99) id BED88599F4; Fri, 15 Jul 2011 13:46:17 -0500 (CDT) Received: from Sidney-Stratton.local (70-36-143-92.dsl.dynamic.sonic.net [70.36.143.92]) by smtp-4.01.com (Postfix) with ESMTPSA id 5C9523BCBF1 for ; Fri, 15 Jul 2011 13:46:17 -0500 (CDT) Message-ID: <4E208AF8.1070805@agliodbs.com> Date: Fri, 15 Jul 2011 11:46:16 -0700 From: Josh Berkus Organization: PostgreSQL Experts Inc. User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2.15) Gecko/20110303 Lightning/1.0b2 Thunderbird/3.1.9 MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: Hardware advice for scalable warehouse db References: In-Reply-To: X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.9 tagged_above=-10 required=5 tests=BAYES_00=-1.9 X-Spam-Level: X-Archive-Number: 201107/162 X-Sequence-Number: 44374 > Just to add to the conversation, there's no real advantage to putting > WAL on SSD. Indexes can benefit from them, but WAL is mosty > seqwuential throughput and for that a pair of SATA 1TB drives at > 7200RPM work just fine for most folks. Actually, there's a strong disadvantage to putting WAL on SSD. SSD is very prone to fragmentation if you're doing a lot of deleting and replacing files. I've implemented data warehouses where the database was on SSD but WAL was still on HDD. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com