RE: Stronger safeguard for archive recovery not to miss data

On Friday, April 2, 2021 11:49 PM Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at> wrote:
> On Thu, 2021-04-01 at 17:25 +0900, Fujii Masao wrote:
> > Thanks for updating the patch!
> >
> > + errhint("Use a backup taken after
> setting wal_level to higher than minimal "
> > + "or recover to the
> > + point in time before wal_level becomes minimal even though it causes
> > + data loss")));
> >
> > ISTM that "or recover to the point in time before wal_level was changed
> > to minimal even though it may cause data loss" sounds better. Thought?
>
> I would reduce it to
>
> "Either use a later backup, or recover to a point in time before \"wal_level\"
> was set to \"minimal\"."
>
> I'd say that we can leave it to the intelligence of the reader to deduce that
> recovering to an earlier time means more data loss.
Thank you. Yet, I prefer the longer version.
For example, the later backup can be another backup that fails during archive recovery
if the user have several backups during wal_level=replica
and it is taken before setting wal_level=minimal, right ?

Like this, giving much information is helpful for better decision taken by user, I thought.

Best Regards,
Takamichi Osumi