X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 9290B5281C for ; Thu, 2 Jun 2005 11:23:20 -0300 (ADT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 12641-09 for ; Thu, 2 Jun 2005 14:23:19 +0000 (GMT) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id 96FAB52802 for ; Thu, 2 Jun 2005 11:23:18 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id j52ENNXX013549; Thu, 2 Jun 2005 10:23:23 -0400 (EDT) To: Himanshu Baweja Cc: pgsql-performance@postgresql.org Subject: Re: Moving pg_xlog In-reply-to: <20050602070209.96753.qmail@web51005.mail.yahoo.com> References: <20050602070209.96753.qmail@web51005.mail.yahoo.com> Comments: In-reply-to Himanshu Baweja message dated "Thu, 02 Jun 2005 00:02:09 -0700" Date: Thu, 02 Jun 2005 10:23:23 -0400 Message-ID: <13548.1117722203@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.006 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200506/39 X-Sequence-Number: 12677 Himanshu Baweja writes: > My database has two scsi disks.... > my current configuration has pg_xlog on disk1 and data on disk2.... > the machine is used for database only.... > now did some logging and came to a conclusion that my disk2(data disk) is getting used around 3 times more than disk1(pg_xlog).... > so wht is recommended... move some of the data to disk1 so that both disks are equally used... by creating tablespaces or let my configuration be whts its currently... iowait is one of the bottlenecks in my application performance..... It seems highly unlikely that putting more stuff on the xlog disk will improve performance --- at least not if your bottleneck is update speed. If it's a read-mostly workload then optimizing xlog writes may not be the most important thing to you. In that case you might want to ignore xlog and try something along the lines of tables on one disk, indexes on the other. regards, tom lane