Received: from localhost (postgresql.org [64.49.215.8]) by postgresql.org (Postfix) with ESMTP id 1A7F94764D2 for ; Tue, 8 Oct 2002 08:57:31 -0400 (EDT) Received: from www.pspl.co.in (www.pspl.co.in [202.54.11.65]) by postgresql.org (Postfix) with ESMTP id 8CC2D476434 for ; Tue, 8 Oct 2002 08:57:29 -0400 (EDT) Received: (from root@localhost) by www.pspl.co.in (8.11.6/8.11.6) id g98Cx7s03859 for ; Tue, 8 Oct 2002 18:29:07 +0530 Received: from daithan (daithan.intranet.pspl.co.in [192.168.7.161]) by www.pspl.co.in (8.11.6/8.11.0) with ESMTP id g98Cx6v03854 for ; Tue, 8 Oct 2002 18:29:07 +0530 From: "Shridhar Daithankar" To: Date: Tue, 08 Oct 2002 18:28:01 +0530 MIME-Version: 1.0 Subject: Re: Hot Backup Reply-To: shridhar_daithankar@persistent.co.in Message-ID: <3DA323B1.3732.155CAB4F@localhost> In-reply-to: X-mailer: Pegasus Mail for Windows (v4.02) Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Content-description: Mail message body X-Virus-Scanned: by AMaViS new-20020517 X-Archive-Number: 200210/444 X-Sequence-Number: 31442 On 8 Oct 2002 at 14:17, Erwan DUROSELLE wrote: > > MvO> http://www.postgresql.org/idocs/index.php?wal.html > - The URL you refer to is the ch11 I was refering to. It seems that this chapter is not as easily understandable as it should... > It says that with WAL, "pg is able to garantee consistency in the case of a crash". > OK, but I think is about /consistency/. > For what I understand, it just says that in the case of a core dump of a server process (improbable) or a power cut (probable) or an unwanted kill -9 (may happen), Pg will not have any corrupted table or index. > > Cool, but not enough. > > As Timur pointed out, I was refering to a disk crash or total loss of a server. > In this case, you loose up to 1 day of data. > > There is a need in "incremental" backup, which backs up only those > > transactions which has been fulfilled after last "full dump" or last > > "incremental dump". These backups should be done quite painlessly - > > just copy some part of WAL, and should be small enough (compared to > > full dump), so they can be done each hour or even more frequently.. > > > > I hope sometime PostgreSQL will support that. :-) Well, there are replication solutions which rsyncs WAL files after they are rotated so two database instances are upto sync with each other at a difference of one WAL file. If you are interested I can post the pdf. I guess that takes care of scenario you plan to avoid.. Bye Shridhar -- Truthful, adj.: Dumb and illiterate. -- Ambrose Bierce, "The Devil's Dictionary"