X-Original-To: pgsql-docs-postgresql.org@localhost.postgresql.org Received: from localhost (mx2.hub.org [200.46.204.254]) by postgresql.org (Postfix) with ESMTP id 914D811F6CF9 for ; Sat, 15 Apr 2006 15:42:39 -0300 (ADT) X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Score: -2.251 X-Spam-Level: X-Spam-Status: No, score=-2.251 required=5 tests=[AWL=0.350, BAYES_00=-2.599, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] Received: from postgresql.org ([200.46.204.71]) by localhost (mx2.hub.org [200.46.204.254]) (amavisd-new, port 10024) with ESMTP id Y3F2+ReLXju0 for ; Sat, 15 Apr 2006 15:42:37 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from candle.pha.pa.us (candle.pha.pa.us [70.90.9.53]) by postgresql.org (Postfix) with ESMTP id 441C411F6CF1 for ; Sat, 15 Apr 2006 15:42:36 -0300 (ADT) Received: (from pgman@localhost) by candle.pha.pa.us (8.11.6/8.11.6) id k3FIgVm10059; Sat, 15 Apr 2006 14:42:31 -0400 (EDT) From: Bruce Momjian Message-Id: <200604151842.k3FIgVm10059@candle.pha.pa.us> Subject: Re: Proposed doc-patch: Identifying the Current WAL file In-Reply-To: To: Jeff Frost Date: Sat, 15 Apr 2006 14:42:31 -0400 (EDT) CC: Tom Lane , Richard Huxton , pgsql-docs@postgresql.org X-Mailer: ELM [version 2.4ME+ PL121 (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-Archive-Number: 200604/18 X-Sequence-Number: 3517 Jeff Frost wrote: > On Sat, 15 Apr 2006, Bruce Momjian wrote: > > > Tom Lane wrote: > > > > No, I am not: > > > > $ touch x1 x2; touch x2 > > $ sleep 2; ls -lt > > total 0 > > -rw-r--r-- 1 root postgres 0 Apr 15 14:04 x1 > > -rw-r--r-- 1 root postgres 0 Apr 15 14:04 x2 > > > > If the write to x2 happens in the first second, but no later writes > > happen, you still see x1 as first, even though x2 is the new one and > > might have WAL data in it. The point is that the test does not have a > > one-second window of showing the wrong answer, meaning I could wait for > > 60 seconds, and still see the wrong WAL file at the top. > > Bruce, what does > > stat x1 x2 > > look like on your system? Which OS? Maybe we need caveats for various OSes? System is BSD/OS: $ touch x1 x2; stat x1 x2 filename: x1 inode: 4547362 device: 18,7 size: 0 type: regular file links: 1 mode: 0644(-rw-r--r--) owner: 0(root) group: 102(postgres) access: Sat Apr 15 14:41:12 2006 modification: Sat Apr 15 14:41:12 2006 change: Sat Apr 15 14:41:12 2006 filename: x2 inode: 4547363 device: 18,7 size: 0 type: regular file links: 1 mode: 0644(-rw-r--r--) owner: 0(root) group: 102(postgres) access: Sat Apr 15 14:41:12 2006 modification: Sat Apr 15 14:41:12 2006 change: Sat Apr 15 14:41:12 2006 And I tried it on Fedora Core 2: bmomjian@x86-linux2:~$ touch x1 x2 ; stat x1 x2 File: `x1' Size: 0 Blocks: 0 IO Block: 8192 regular empty file Device: 11h/17d Inode: 24707337 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 7078/bmomjian) Gid: ( 100/ users) Access: 2006-04-15 11:41:53.000000000 -0700 Modify: 2006-04-15 11:41:53.000000000 -0700 Change: 2006-04-15 11:41:53.000000000 -0700 File: `x2' Size: 0 Blocks: 0 IO Block: 8192 regular empty file Device: 11h/17d Inode: 24707338 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 7078/bmomjian) Gid: ( 100/ users) Access: 2006-04-15 11:41:53.000000000 -0700 Modify: 2006-04-15 11:41:53.000000000 -0700 Change: 2006-04-15 11:41:53.000000000 -0700 -- Bruce Momjian http://candle.pha.pa.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +