Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id 4D56A133655C for ; Fri, 18 Mar 2011 12:48:11 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.251]) (amavisd-maia, port 10024) with ESMTP id 33699-10 for ; Fri, 18 Mar 2011 15:48:04 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from exprod7og101.obsmtp.com (exprod7og101.obsmtp.com [64.18.2.155]) by mail.postgresql.org (Postfix) with ESMTP id 6E1F4133616B for ; Fri, 18 Mar 2011 12:48:02 -0300 (ADT) Received: from source ([209.85.215.182]) (using TLSv1) by exprod7ob101.postini.com ([64.18.6.12]) with SMTP ID DSNKTYN+r1LVbE+aQBw5B0x2as8ZbfncNGr6@postini.com; Fri, 18 Mar 2011 08:48:03 PDT Received: by eyg7 with SMTP id 7so1028693eyg.13 for ; Fri, 18 Mar 2011 08:47:53 -0700 (PDT) Received: by 10.14.119.74 with SMTP id m50mr16911eeh.72.1300463271954; Fri, 18 Mar 2011 08:47:51 -0700 (PDT) Received: from [192.168.1.183] (dsl-hkibrasgw2-ff7ac300-240.dhcp.inet.fi [88.195.122.240]) by mx.google.com with ESMTPS id v1sm14527eeh.13.2011.03.18.08.47.49 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 18 Mar 2011 08:47:50 -0700 (PDT) Message-ID: <4D837EA2.2070205@enterprisedb.com> Date: Fri, 18 Mar 2011 17:47:46 +0200 From: Heikki Linnakangas User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; fi-FI; rv:1.9.1.16) Gecko/20101226 Icedove/3.0.11 MIME-Version: 1.0 To: Kevin Grittner CC: Simon Riggs , MARK CALLAGHAN , Markus Wanner , Alvaro Herrera , Andrew Dunstan , 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> In-Reply-To: <4D832B4D020000250003BA98@gw.wicourts.gov> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.119 tagged_above=-5 required=5 tests=BAYES_00=-1.9, FS_REPLICA=3.599, RCVD_IN_DNSWL_MED=-2.3, SARE_SPEC_REPLICA=0.72 X-Spam-Level: X-Archive-Number: 201103/1141 X-Sequence-Number: 184391 On 18.03.2011 16:52, Kevin Grittner wrote: > Simon Riggs wrote: > >> In PostgreSQL other users cannot observe the commit until an >> acknowledgement has been received. > > Really? I hadn't picked up on that. That makes for a lot of > complication on crash-and-recovery of a master, but if we can pull > it off, that's really cool. If we do that and MySQL doesn't, we > definitely don't want to use the same terminology they do, which > would imply the same behavior. To be clear: other users cannot observe the commit until standby acknowledges it - unless the master crashes while waiting for the acknowledgment. If that happens, the commit will be visible to everyone after recovery. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com