Received: from localhost (maia-5.hub.org [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id 5AC169FB52D for ; Thu, 21 Jun 2007 14:12:00 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-maia, port 10024) with ESMTP id 32691-01-2 for ; Thu, 21 Jun 2007 14:11:53 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from main2.mycybernet.net (main2.mycybernet.net [209.222.63.140]) by postgresql.org (Postfix) with ESMTP id C48B49FB4EC for ; Thu, 21 Jun 2007 14:11:54 -0300 (ADT) Received: from 227-54-222-209.mycybernet.net ([209.222.54.227] helo=phlogiston.dydns.org) by main2.mycybernet.net with esmtp (Exim 4.62) (envelope-from ) id 1I1QCH-0004NL-Ro for pgsql-performance@postgresql.org; Thu, 21 Jun 2007 13:11:53 -0400 Received: by phlogiston.dydns.org (Postfix, from userid 1000) id 6662A404E; Thu, 21 Jun 2007 13:11:48 -0400 (EDT) Date: Thu, 21 Jun 2007 13:11:48 -0400 From: Andrew Sullivan To: pgsql-performance@postgresql.org Subject: Re: Performance query about large tables, lots of concurrent access Message-ID: <20070621171148.GC5500@phlogiston.dyndns.org> References: <4676DD57.7070304@metacarta.com> <20070620175300.GN30369@alvh.no-ip.org> <46796A08.8080601@metacarta.com> <200706201425.28557.sthomas@leapfrogonline.com> <46799C45.7080805@metacarta.com> <4679AE24.9070005@g2switchworks.com> <4679B6C7.3080207@metacarta.com> <467A9CE5.508@g2switchworks.com> <467AA77D.3030204@metacarta.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <467AA77D.3030204@metacarta.com> User-Agent: Mutt/1.5.9i X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200706/476 X-Sequence-Number: 25509 On Thu, Jun 21, 2007 at 12:29:49PM -0400, Karl Wright wrote: > I checked the disk picture - this is a RAID disk array with 6 drives, > with a bit more than 1Tbyte total storage. 15,000 RPM. It would be > hard to get more/faster disk than that. What kind of RAID? It's _easy_ to get faster disk that 6 drives in RAID5, even if they're 15,000 RPM. The rotation speed is the least of your problems in many RAID implementations. A -- Andrew Sullivan | ajs@crankycanuck.ca "The year's penultimate month" is not in truth a good way of saying November. --H.W. Fowler