Re: testing cvs HEAD - HS/SR - xlog timeline 0 pg_xlogfile_name_offset

Fujii Masao <masao.fujii@gmail.com>

From: Fujii Masao <masao.fujii@gmail.com>
To: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
Cc: Erik Rijkers <er@xs4all.nl>, pgsql-hackers@postgresql.org
Date: 2010-02-25T09:25:48Z
Lists: pgsql-hackers
On Thu, Feb 25, 2010 at 5:10 PM, Heikki Linnakangas
<heikki.linnakangas@enterprisedb.com> wrote:
> A quick fix would be to just throw an error if you try to use
> pg_xlog_filename() during hot standby. But there seems to be good
> reasons to call pg_xlog_filename() during hot standby, given that both
> of you ran into the same issue. What exactly were you trying to achieve
> with it?

Nothing ;) Frankly I just found that problem while testing the
combination of SR and system administration functions. But on
second thought, calling pg_xlogfile_name() during HS seems useful
to remove old WAL files from the archive that is shared from
multiple standbys. In this case, '%r' in restore_command cannot
be used, so we would need to calculate the name of the WAL files
that are not required for the subsequent recovery yet by using
pg_xlogfile_name() and pg_controldata etc.

Regards,

-- 
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center