Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id 01F781337999 for ; Fri, 18 Mar 2011 16:34:34 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.29]) (amavisd-maia, port 10024) with ESMTP id 19400-05 for ; Fri, 18 Mar 2011 19:34:24 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from gw.wicourts.gov (gwmta.wicourts.gov [165.219.244.99]) by mail.postgresql.org (Postfix) with ESMTP id 4AB1E133655C for ; Fri, 18 Mar 2011 16:34:23 -0300 (ADT) Received: from Courts-MTA by gw.wicourts.gov with Novell_GroupWise; Fri, 18 Mar 2011 14:34:22 -0500 Message-Id: <4D836D6A020000250003BAE4@gw.wicourts.gov> X-Mailer: Novell GroupWise Internet Agent 8.0.1 Date: Fri, 18 Mar 2011 14:34:18 -0500 From: "Kevin Grittner" To: "Simon Riggs" , "Markus Wanner" Cc: "Alvaro Herrera" , "Andrew Dunstan" , "Heikki Linnakangas" , "MARK CALLAGHAN" , "Aidan Van Dyk" , "pgsql-hackers" Subject: Re: Re: [COMMITTERS] pgsql: Efficient transaction-controlled synchronous replication. References: <4D741441.2090704@dunslane.net> <1299454125.1696.6138.camel@ebony> <4D74896C.5030402@enterprisedb.com> <4D74DDFA.70800@dunslane.net> <4D74E584.7080409@enterprisedb.com> <4D74E9FA.7070202@dunslane.net> <4D74F3AE.9000802@dunslane.net> <4D74FDEC.5040406@enterprisedb.com> <4D74FF15.1070804@dunslane.net> <1299513979-sup-1987@alvh.no-ip.org> <4D832571.5030808@bluegap.ch> <1300457958.18619.13780.camel@ebony> <4D832B4D020000250003BA98@gw.wicourts.gov> <4D837EA2.2070205@enterprisedb.com> <1300465171.18619.15193.camel@ebony> <4D83B02A.5090105@bluegap.ch> <1300476590.18619.18115.camel@ebony> In-Reply-To: <1300476590.18619.18115.camel@ebony> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=2.409 tagged_above=-5 required=5 tests=BAYES_00=-1.9, FS_REPLICA=3.599, SARE_SPEC_REPLICA=0.72, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: ** X-Archive-Number: 201103/1166 X-Sequence-Number: 184416 Simon Riggs wrote: > On Fri, 2011-03-18 at 20:19 +0100, Markus Wanner wrote: >> >>> Simon Riggs wrote: >> >>>> In PostgreSQL other users cannot observe the commit until an >> >>>> acknowledgement has been received. >> >> On other nodes as well? To me that means the standby needs to >> hold back COMMIT of an ACKed transaction, until receives a re-ACK >> from the master, that it committed the transaction there. How >> else could the slave know when to commit its ACKed transactions? > > We could do that easily enough, actually, if we wished. > > Do we wish? +1 If we're going out of our way to suppress it on the master until the COMMIT returns, it shouldn't be showing on the replicas before that. -Kevin