Re: Updated backup APIs for non-exclusive backups

Greetings,

* David Steele (david(at)pgmasters(dot)net) wrote:
> On 11/26/18 12:31 AM, Laurenz Albe wrote:
> >If there is a crash during the backup procedure, the backup is bad.
> >Doesn't matter during which part of the backup procedure it happens.
>
> Yes, but in this case with exclusive backups your cluster also will not
> start. That's a lot different than a bad backup because you should have
> many backups and a way to mark when they are complete. If your cluster
> requires manual intervention to start because a backup was in progress
> that's not a good thing.
>
> I'm of the opinion that we should remove the exclusive option for PG12. The
> recovery changes recently committed will completely break any automated
> recovery written for PG <= 11 so we might as go all the way.

Yeah, after chatting with David about that this morning, I agree.
Breaking everything around how restores works means that anyone doing
backups today needs to re-evaluate their restore procedures, even if
it's not an automated script, so it makes sense to also remove the
deprecated exclusive backup mode at the same time.

> Requiring non-exclusive backup will be an easy change for tools that already
> understand non-exclusive backup, which has been available in the last three
> versions of Postgres.
>
> The exclusive backup method tries to make a hard problem look simple but
> does not succeed and causes issues besides. Performing backups properly
> *is* hard and we don't do anyone a service by making it look like something
> can be done with a trivial bash script.

+1

Thanks!

Stephen