From mdavidson@icsolutions.com Thu Jan 27 20:10:00 2011 Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id A26D01337B5E for ; Thu, 27 Jan 2011 16:10:00 -0400 (AST) 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 67635-08 for ; Thu, 27 Jan 2011 20:09:53 +0000 (UTC) X-Greylist: delayed 00:05:22.332084 by SQLgrey-1.7.6 Received: from polaris1.ics.loc (polaris.icsolutions.com [174.47.150.20]) by mail.postgresql.org (Postfix) with ESMTP id 14ECA1337B4E for ; Thu, 27 Jan 2011 16:09:53 -0400 (AST) Received: from [172.26.15.66] (172.26.15.66) by polaris.icsolutions.com (172.26.16.20) with Microsoft SMTP Server id 8.1.436.0; Thu, 27 Jan 2011 14:04:30 -0600 Message-ID: <4D41CFCD.4050402@icsolutions.com> Date: Thu, 27 Jan 2011 14:04:29 -0600 From: Melvin Davidson User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.13) Gecko/20101207 Thunderbird/3.1.7 MIME-Version: 1.0 To: Subject: Clarification of pg_cotroldata output Content-Type: multipart/alternative; boundary="------------030109070600090605050704" X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.909 tagged_above=-10 required=5 tests=BAYES_00=-1.9, HTML_MESSAGE=0.001, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201101/177 X-Sequence-Number: 36617 --------------030109070600090605050704 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit *Can someone please clarify? When I execute pg_control on a warm standby cluster, I notice that often, "Time of latest checkpoint:" lags behind "pg_control last modified:". Is it documented anywhere the difference between "pg_control last modified:" and "Time of latest checkpoint:" ? Thanks in advance! Melvin * --------------030109070600090605050704 Content-Type: text/html; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit
Can someone please clarify?
When I execute pg_control on a warm standby cluster, I notice that often,
"Time of latest checkpoint:" lags behind "pg_control last modified:".

Is it documented anywhere the difference between "pg_control last modified:"
and "Time of latest checkpoint:" ?

Thanks in advance!
Melvin

--------------030109070600090605050704-- From Kevin.Grittner@wicourts.gov Mon Jan 31 18:49:05 2011 Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id 6D6481337B90 for ; Mon, 31 Jan 2011 14:49:05 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.243]) (amavisd-maia, port 10024) with ESMTP id 35432-08 for ; Mon, 31 Jan 2011 18:48:58 +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 D93DA1336971 for ; Mon, 31 Jan 2011 14:48:57 -0400 (AST) Received: from Courts-MTA by gw.wicourts.gov with Novell_GroupWise; Mon, 31 Jan 2011 12:48:57 -0600 Message-Id: <4D46AFAF020000250003A038@gw.wicourts.gov> X-Mailer: Novell GroupWise Internet Agent 8.0.1 Date: Mon, 31 Jan 2011 12:48:47 -0600 From: "Kevin Grittner" To: "Melvin Davidson" , Subject: Re: Clarification of pg_cotroldata output References: <4D41CFCD.4050402@icsolutions.com> In-Reply-To: <4D41CFCD.4050402@icsolutions.com> 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=-4.21 tagged_above=-10 required=5 tests=BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201101/198 X-Sequence-Number: 36638 Melvin Davidson wrote: > When I execute pg_control on a warm standby cluster, I notice that > often, "Time of latest checkpoint:" lags behind "pg_control last > modified:". > > Is it documented anywhere the difference between "pg_control last > modified:" and "Time of latest checkpoint:" ? If it's documented, I haven't found it yet. I generally find the labels to be pretty descriptive, though. "pg_control last modified" is the last time the server wrote control information out to the disk. "Time of latest checkpoint" is the last time a checkpoint had been performed at the point when the control data was last written. -Kevin