Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id 4F265B5DBDB for ; Thu, 30 Jun 2011 14:38:15 -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 47900-09 for ; Thu, 30 Jun 2011 17:38:08 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from smtp-2.01.com (smtp-2.01.com [38.102.63.181]) by mail.postgresql.org (Postfix) with ESMTP id A0B1AB5DBD0 for ; Thu, 30 Jun 2011 14:38:08 -0300 (ADT) Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp-2.01.com (Postfix) with ESMTP id 3098D1ADE9F for ; Thu, 30 Jun 2011 12:38:08 -0500 (CDT) Received: from smtp-2.01.com ([127.0.0.1]) by localhost (smtp-2.01.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id txTSFc2NPUmG for ; Thu, 30 Jun 2011 12:38:08 -0500 (CDT) Received: by smtp-2.01.com (Postfix, from userid 99) id 167C21AD7DC; Thu, 30 Jun 2011 12:38:08 -0500 (CDT) Received: from Sidney-Stratton.local (70-36-143-92.dsl.dynamic.sonic.net [70.36.143.92]) by smtp-2.01.com (Postfix) with ESMTPSA id B450D1ADE9F for ; Thu, 30 Jun 2011 12:38:07 -0500 (CDT) Message-ID: <4E0CB47E.7070909@agliodbs.com> Date: Thu, 30 Jun 2011 10:38:06 -0700 From: Josh Berkus Organization: PostgreSQL Experts Inc. User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2.15) Gecko/20110303 Lightning/1.0b2 Thunderbird/3.1.9 MIME-Version: 1.0 To: pgsql-hackers@postgresql.org Subject: Re: time-delayed standbys References: <26007.1303309175@sss.pgh.pa.us> <27149.1303312506@sss.pgh.pa.us> In-Reply-To: X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.9 tagged_above=-5 required=5 tests=BAYES_00=-1.9 X-Spam-Level: X-Archive-Number: 201106/2370 X-Sequence-Number: 191083 On 6/30/11 10:25 AM, Robert Haas wrote: > So I think keeping it defined it terms of time is the > right way forward, even though the need for external time > synchronization is, certainly, not ideal. Actually, when we last had the argument about time synchronization, Kevin Grittner (I believe) pointed out that unsynchronized replication servers have an assortment of other issues ... like any read query involving now(). As the person who originally brought up this hurdle, I felt that his argument defeated mine. Certainly I can't see any logical way to have time delay in the absence of clock synchronization of some kind. Also, I kinda feel like this discussion seems aimed at overcomplicating a feature which only a small fraction of our users will ever use. Let's keep it as simple as possible. As for delay on streaming replication, I'm for it. I think that post-9.1, thanks to pgbasebackup, the number of our users who are doing archive log shipping is going to drop tremendously. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com