Re: Fast promotion not used when doing a recovery_target PITR restore?

On 2017-06-28 06:04:23 +0900, Michael Paquier wrote:
> On Wed, Jun 28, 2017 at 3:44 AM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> > I'm far from convinced by this. By now WAL replay with checkpointer,
> > bgwriter, etc. active is actually *more* tested than the cases without
> > it. The likelihood of bugs is higher in the less frequently exercised
> > paths, and given that replication exercises the situation with all those
> > processes active on a continuous basis, I'm fairly unconvinced by your
> > argument.
>
> Crash recovery is the last thing where failures should never happen.
> Don't you think that it should remain simple as it has been designed
> originally? It seems to me that the argument for keeping things simple
> has higher priority than performance in being able to reconnect by
> delaying the checkpoint.

You seem to completely argue besides my point that the replication path
is *more* robust by now? And there's plenty scenarios where a faster
startup is quite crucial for performance. The difference between an
immediate shutdown + recovery without checkpoint to a fast shutdown can
be very large, and that matters a lot for faster postgres updates etc.

Andres