Received: from localhost (unknown [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id D1ED59F9EFE for ; Sat, 8 Sep 2007 03:26:55 -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 11995-09 for ; Sat, 8 Sep 2007 03:26:49 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from smtp.nildram.co.uk (smtp.nildram.co.uk [195.112.4.54]) by postgresql.org (Postfix) with ESMTP id AA0939F9E9C for ; Sat, 8 Sep 2007 03:26:50 -0300 (ADT) Received: from [192.168.0.3] (85-211-21-1.dyn.gotadsl.co.uk [85.211.21.1]) by smtp.nildram.co.uk (Postfix) with ESMTP id 415532B6058; Sat, 8 Sep 2007 07:26:40 +0100 (BST) Subject: Re: DRBD and Postgres: how to improve the perfomance? From: Simon Riggs To: Bernd Helmle Cc: mfatticcioni@mbigroup.it, pgsql-performance@postgresql.org In-Reply-To: <2C070D1C3970467FF64F6B6A@imhotep.credativ.de> References: <2C070D1C3970467FF64F6B6A@imhotep.credativ.de> Content-Type: text/plain Date: Sat, 08 Sep 2007 07:28:24 +0100 Message-Id: <1189232904.4281.19.camel@ebony.site> Mime-Version: 1.0 X-Mailer: Evolution 2.8.2 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200709/141 X-Sequence-Number: 26686 On Fri, 2007-09-07 at 23:54 +0200, Bernd Helmle wrote: > --On Freitag, September 07, 2007 20:00:16 +0100 Simon Riggs > wrote: > > > On Fri, 2007-09-07 at 11:37 +0200, Maila Fatticcioni wrote: > > > >> protocol C; > > > > Try protocol B instead. > > But that would have an impact on transaction safety, wouldn't it? It will > return immediately after reaching the remote buffer cache and you can't be > sure your data hits the remote disk. You're right, but the distinction is a small one. What are the chances of losing two independent servers within a few milliseconds of each other? If performance is an issue it is a particularly important distinction. -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com