Re: Remove Deprecated Exclusive Backup Mode

On Mon, Feb 25, 2019 at 11:23 AM Stephen Frost <sfrost(at)snowman(dot)net> wrote:
> If that argument did matter, we could go back and find the prior
> discussions about the issues around the exclusive backup mode and about
> removing it, or next year we could point to this thread about it, or the
> year after, and say "well, we talked about it a lot, so now let's just
> do it", but it all ends up looking the same to our users unless we
> actually write into some kind of user-facing documentation or WARNINGs
> or similar that something is going away.

That's true. But nobody's objecting to strengthening the warnings in
the documentation. People are objecting to removing the thing itself.

> This isn't a fair argument either because we're having this *after* the
> new API was implemented for backup- namely non-exclusive mode, which
> *did* give people something better to use instead.

There are several people who are saying that doesn't meet all their
needs, giving reasons why it's problematic, and suggesting things that
could be done to make it less problematic. It's not OK to say "we can
remove exclusive backup mode because now we have non-exclusive backup
mode" unless other people actually agree that all the use cases are
covered, and it appears that they don't.

> I disagree quite a bit with this statement- the existing documentation
> is absolutely horrid and needs to be completely ripped out and rewritten
> and maintaining the exclusive backup mode in such a rewrite would
> absolutely be a *lot* of additional work.
>
> We actually took a shot at trying to improve the documentation while
> continuing to cover both the exclusive and the non-exclusive mode and
> it's hugely painful.

Well, perhaps that's pain you need to incur. The alternative seems to
be to rip out something that people don't want ripped out.

> I used to be one of those people. I know that it looks fine and it
> certainly seems appealing but having gone through bad experiences with
> it, and seen others stumble through those same experiences time and time
> again, I've learned that it really is an issue, and one that I would
> very much like to avoid causing future users to stumble over.

Sure, that sounds great. But the way to do that is to continue
improving the system until exclusive-mode backups really are not a
useful thing any more, not to remove it while there are still a lot of
people relying on it who can offer tangible explanations for their
choice to do so.

It feels to me like you are portraying the increasing number of people
objecting to this change as naive or foolish or at least not as
enlightened as you are, and I really object to that. I happen to
think that people like Christophe Pettus and Fujii Masao and Laurenz
Albe are smart people whose opinions ought to be taken as just as
valid as your own.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company