Re: Remove Deprecated Exclusive Backup Mode

Greetings,

* Christophe Pettus (xof@thebuild.com) wrote:
> > On Feb 25, 2019, at 08:55, Stephen Frost <sfrost@snowman.net> wrote:
> >
> > I honestly do doubt that they have had the same experiences that I have
> > had
>
> Well, I guarantee you that no two people on this list have had identical experiences. :)

Indeed! :)

> I certainly have been bitten by the problems with the current system.  But the resistance to major version upgrades
is*huge*, and I'm strongly biased against anything that will make that harder.  I'm not sure I'm communicating how big
aproblem telling many large installations, "If you move to v12/13/etc., you will have to change your backup system" is
goingto be. 

Aren't they going to need to make a change for v12 now anyway?

Hopefully they're regularly testing their backups by doing a restore of
them, and dropping a recovery.conf into the directory of a v12 system
after restore will do exactly nothing and they'll get errors complaining
about how they need to provide a restore_command.

That's actually what prompted bringing this painful topic up again-
there's a large change being done to how backup/restore with PG is done
(the recovery.conf file is going away), and people who have written any
kind of automation (or even just documented procedures...) around that
will have to update their systems.  At least from my perspective, making
them have to do such an update once, instead of once now and another
time in the future when we remove exclusive backup (or figure out a way
to do it that's safe and update the instructions for how to do it
right...), is the better option.

* Bruce Momjian (bruce@momjian.us) wrote:
> On Mon, Feb 25, 2019 at 11:33:33AM -0500, Stephen Frost wrote:
> > I don't want to see more users stumbling over the issues with the
> > exclusive backup interface.  A better interface exists, and has existed
> > since 9.6.
>
> Do you really think we would be having this discussion if the
> non-exclusive backup method was unequivocally better?  It is better for
> some use-cases, and impossible for others.

Based on Christophe's comment above, anything which required users to
make a change on upgrade to their backup system would be cause to have
this discussion, which likely includes most possible solutions to the
issues with exclusive backup too, unfortunately..

> Also, you can't say it will have no impact for five years on people who
> do not upgrade.  The impact will be that they will have no new Postgres
> features for five years.

I don't think I made the claim that there wouldn't be any impact for
five years, I said they would continue to have support for five years.

Also, this is exactly what we tell them for any other breaking change
(such as removal of recovery.conf).

> I am not taking a stance on this issue, but making unclear statements
> isn't helping the discussion.

It's not my intent to make unclear statements, so I certainly appreicate
you, and anyone else, pointing out when I do.  I'm happy to clarify.

Thanks!

Stephen