To: Mike Atkin <mike.atkin@gmail.com>
cc: pgsql-admin@postgresql.org
Subject: Re: WAL archiving disaster 
In-reply-to: <BANLkTimqdfk3RxWUAUmqhWtDd+71gDx2gg@mail.gmail.com> 
References: <BANLkTimqdfk3RxWUAUmqhWtDd+71gDx2gg@mail.gmail.com>
Comments: In-reply-to Mike Atkin <mike.atkin@gmail.com>
	message dated "Tue, 12 Apr 2011 17:33:37 +0100"
Date: Tue, 12 Apr 2011 20:40:38 -0400
Message-ID: <20370.1302655238@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Mike Atkin <mike.atkin@gmail.com> writes:
> So... normally this would be curtains for the database but the missing
> segment is from a 4 hour period of practically zero activity.  It was
> only archived because it hit the archive_timeout.  Is there any way I
> can force postgres to ignore this segment and attempt to redo the rest
> of the logs.  I realise this may leave the database terminally
> inconsistent but my focus is on retrieving as much of the data as
> possible for re-entry rather than getting a functional system out the
> other end.

If you're willing to assume there were no updates in that interval,
you could try generating a dummy WAL segment having the correct page
headers and no contents except an XLOG_SWITCH record.  I don't know
of any handy tools for that unfortunately.

			regards, tom lane