X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (mx2.hub.org [200.46.204.254]) by postgresql.org (Postfix) with ESMTP id 7165511F6109 for ; Fri, 14 Apr 2006 15:02:13 -0300 (ADT) X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Score: -0.402 X-Spam-Level: X-Spam-Status: No, score=-0.402 required=5 tests=[AWL=-1.754, BAYES_00=-2.599, FORGED_RCVD_HELO=0.135, SPF_HELO_SOFTFAIL=2.432, SPF_SOFTFAIL=1.384] Received: from postgresql.org ([200.46.204.71]) by localhost (mx2.hub.org [200.46.204.254]) (amavisd-new, port 10024) with ESMTP id 9DFGDxcPypek for ; Fri, 14 Apr 2006 15:01:58 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from zoraida.natserv.net (p65-147.acedsl.com [66.114.65.147]) by postgresql.org (Postfix) with ESMTP id 04B1F11F6C68 for ; Fri, 14 Apr 2006 15:01:57 -0300 (ADT) Received: from zoraida.natserv.net (localhost.natserv.net [127.0.0.1]) by zoraida.natserv.net (Postfix) with ESMTP id 9E8E7B81F; Fri, 14 Apr 2006 14:01:57 -0400 (EDT) Received: from 35st-server.simplicato.com (static-71-249-233-130.nycmny.east.verizon.net [71.249.233.130]) by zoraida.natserv.net (Postfix) with ESMTP id 3A0D9B81D; Fri, 14 Apr 2006 14:01:57 -0400 (EDT) References: <443DA715.4060606@gmail.com> <9549.1144903344@sss.pgh.pa.us> <20060414055923.GX49405@pervasive.com> <20060414114911.GG32678@mathom.us> Message-ID: X-Mailer: http://www.courier-mta.org/cone/ From: Francisco Reyes To: Michael Stone Cc: pgsql-performance@postgresql.org Subject: Re: Inserts optimization? Date: Fri, 14 Apr 2006 14:01:56 -0400 Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="US-ASCII" Content-Disposition: inline Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV using ClamSMTP X-Archive-Number: 200604/341 X-Sequence-Number: 18425 Michael Stone writes: > I guess the first question is why 2 hot spares? Because we are using RAID 10 > larger array with more spindles with outperform a smaller one with > fewer, regardless of RAID level (assuming a decent battery-backed > cache). Based on what I have read RAID 10 is supposed to be better with lots of random access. > 5 RAID5 > 2 RAID1 > 1 spare That is certainly something worth considering... Still I wonder if 2 more spindles will help enough to justify going to RAID 5. My understanding is that RAID10 has simpler computations requirements which is partly what makes it better for lots of random read/write.