Re: patch proposal

On Wed, Aug 17, 2016 at 11:27 PM, Stephen Frost <sfrost(at)snowman(dot)net> wrote:

> Venkata,
>
> * Venkata B Nagothi (nag1010(at)gmail(dot)com) wrote:
> > Agreed. Additional option like "pause" would. As long as there is an
> option
> > to ensure following happens if the recovery target is not reached -
> >
> > a) PG pauses the recovery at the end of the WAL
> > b) Generates a warning in the log file saying that recovery target point
> > is not reached (there is a patch being worked upon on by Thom on this)
> > c) Does not open-up the database exiting from the recovery process by
> > giving room to resume the replay of WALs
>
> One thing to consider is just how different this is from simply bringing
> PG up as a warm standby instead, with the warning added to indicate if
> the recovery point wasn't reached.
>

I am referring to a specific scenario (performing point-in time recovery)
where-in a DBA attempts to bring up a standalone PG instance by restoring
the backup and performing recovery to a particular recover target (XID,
time or a named restore point) in the past by replaying all the available
WAL archives, which is not quite possible through a warm-standby setup.

Warm standby is more of a high-availability solution and i do not think so,
it addresses PITR kind of situation.

I will share more details defining PG behaviour across various recovery
scenarios (as asked by David Steele) when using various recovery*
parameters. Will also explain what difference the proposed patch could make.

Regards,

Venkata B N
Fujitsu Australia