Re: PITR Recovery Question

On Jun 4, 2010, at 7:05 , Gnanakumar wrote:
>> If some of those WAL segments still reside in pg_xlog, you'll either need
> to teach your restore_command to fetch them from there. Note that you cannot
> recover "in reverse".
>
> My pg_xlog/ and walarchive/ directory locations are
> "/usr/local/pgsql/data/pg_xlog" and "/mnt/pitr/walarchive" respectively.
>
> If my normal restore command is: restore_command='cp
> "/mnt/pitr/walarchive/%f "%p"', how should I instruct restore command to
> fetch?  Should I just replace this with something like restore_command='cp
> /usr/local/pgsql/data/pg_xlog/%f "%p"'.  Also you have mentioned that we
> cannot recover "in reverse", what I understand from this is that even though
> if I replace the restore command pointing to pg_xlog/ directory, this will
> not work out in this situation?  Is my understanding right?

If you point it at a cluster's own pg_xlog directory, it won't work.

You might want to re-ead the section on the recovery process in the PTITR documentation, at
http://www.postgresql.org/docs/8.4/interactive/continuous-archiving.html#BACKUP-PITR-RECOVERY

If you have further questions, please take this discussion to pgsql-general.

best regards,
Florian Pflug