Reply-To: <gnanam@zoniac.com>
From: "Gnanakumar" <gnanam@zoniac.com>
To: "'Kevin Grittner'" <Kevin.Grittner@wicourts.gov>,
	<pgsql-admin@postgresql.org>
Cc: <fgp@phlo.org>
References: <4C0A141A0200002500032037@gw.wicourts.gov>
In-Reply-To: <4C0A141A0200002500032037@gw.wicourts.gov>
Subject: Re: PITR Recovery Question
Date: Tue, 8 Jun 2010 10:52:33 +0530
Organization: Zoniac Software Private Limited
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Hi Kevin,

Thanks for the clarification.

> kevin@kevin-desktop:~$ true
> kevin@kevin-desktop:~$ echo $?
> 0

Yes, my OS also has got this executable and is working.

Regards,
Gnanam

-----Original Message-----
From: Kevin Grittner [mailto:Kevin.Grittner@wicourts.gov] 
Sent: Saturday, June 05, 2010 7:39 PM
To: pgsql-admin@postgresql.org; gnanam@zoniac.com
Cc: fgp@phlo.org
Subject: RE: [ADMIN] PITR Recovery Question

"Gnanakumar"  wrote:
 
> I couldn't able to get this particular step clearly: "One trick
> would be to temporarily change your archive_command to 'true',
> delete all files from your archive, and then change the command
> back ". Can you please clarify and explain on this?
 
Based on other statements you've made, this isn't a trick you want to
use; just make space in the archive directory, let archiving catch
up, and then take a fresh base backup.
 
That said, this trick is a way to tell PostgreSQL the archive was
successful, even though it wasn't actually copied.  This is
occassionally a useful trick to clear out a backlog of WAL files very
quickly, at the cost of creating a gap in your WAL archive.  Your OS
likely has an executable and/or a shell builtin named "true" which
does nothing except return the "success" exit code of zero.  If you
have such a command on your OS and you set your archive command to
that, PostgreSQL will blast through cleaning up old WAL files.
 
kevin@kevin-desktop:~$ true
kevin@kevin-desktop:~$ echo $?
0
 
But since you said you can copy off the contents of your archive
directory and delete to make room, that's clearly the way to go.
 
-Kevin