X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 6AFC89DCA79 for ; Tue, 21 Mar 2006 18:23:14 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 76722-04 for ; Tue, 21 Mar 2006 18:23:16 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from exchange.g2switchworks.com (mail.g2switchworks.com [63.87.162.25]) by postgresql.org (Postfix) with ESMTP id 3CCE69DC809 for ; Tue, 21 Mar 2006 18:23:12 -0400 (AST) Received: from 10.10.1.37 ([10.10.1.37]) by exchange.g2switchworks.com ([10.10.1.2]) with Microsoft Exchange Server HTTP-DAV ; Tue, 21 Mar 2006 22:23:14 +0000 Received: from state.g2switchworks.com by mail.g2switchworks.com; 21 Mar 2006 16:23:14 -0600 Subject: Re: Migration study, step 1: bulk write performance From: Scott Marlowe To: Tom Lane Cc: Ron , Mikael Carneholm , pgsql-performance@postgresql.org In-Reply-To: <2262.1142978185@sss.pgh.pa.us> References: <7F10D26ECFA1FB458B89C5B4B0D72C2B088286@sesrv12.wirelesscar.com> <1142973890.24487.510.camel@localhost.localdomain> <7.0.1.0.2.20060320161133.03a0b5a8@earthlink.net> <1142975962.17883.203.camel@state.g2switchworks.com> <2262.1142978185@sss.pgh.pa.us> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1142979794.17883.205.camel@state.g2switchworks.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Tue, 21 Mar 2006 16:23:14 -0600 X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.145 required=5 tests=[AWL=0.144, UNPARSEABLE_RELAY=0.001] X-Spam-Score: 0.145 X-Spam-Level: X-Archive-Number: 200603/432 X-Sequence-Number: 17869 On Tue, 2006-03-21 at 15:56, Tom Lane wrote: > Scott Marlowe writes: > > I've also found that modest increases in commit_siblings and > > commit_delay help a lot on certain types of imports. > > On a data import? Those really should have zero effect on a > single-process workload. Or are you doing multiple concurrent imports? That, and it's a machine that's doing other things. Also, a lot of the imports are NOT bundled up into groups of transactions. i.e. lots and lots of individual insert queries.