Re: parallelizing the archiver - Mailing list pgsql-hackers

From Magnus Hagander
Subject Re: parallelizing the archiver
Date
Msg-id CABUevExxuxPrma7PQXa+t9ot1sZ6TZfzZG-ry0ivifabCySB=A@mail.gmail.com
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In response to Re: parallelizing the archiver  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: parallelizing the archiver  (Stephen Frost <sfrost@snowman.net>)
List pgsql-hackers


On Thu, Oct 21, 2021 at 11:05 PM Robert Haas <robertmhaas@gmail.com> wrote:
On Thu, Oct 21, 2021 at 4:29 PM Stephen Frost <sfrost@snowman.net> wrote:
> restore_command used to be in recovery.conf, which disappeared with v12
> and it now has to go into postgresql.auto.conf or postgresql.conf.
>
> That's a huge breaking change.

Not in the same sense. Moving the functionality to a different
configuration file can and probably did cause a lot of problems for
people, but the same basic functionality was still available.

Yeah.

And as a bonus it got a bunch of people to upgrade their backup software that suddenly stopped working. Or in some case, to install backup software instead of using the hand-rolled scripts. So there were some good side-effects specifically to breaking it as well.



(Also, I'm pretty sure that the recovery.conf changes would have
happened years earlier if there hadn't been backward compatibility
concerns, from Simon in particular. So saying that there was "hardly
any complaint raised" in that case doesn't seem to me to be entirely
accurate.)

> > Also, more to the point, when there's a need to break backward
> > compatibility in order to get some improvement, it's worth
> > considering, but here there just isn't.
>
> There won't be any thought towards a backwards-incompatible capability
> if everyone is saying that we can't possibly break it.  That's why I was
> commenting on it.

I can't speak for anyone else, but that is not what I am saying. I am
open to the idea of breaking it if we thereby get some valuable
benefit which cannot be obtained otherwise. But Nathan has now
implemented something which, from the sound of it, will allow us to
obtain all of the available benefits with no incompatibilities. If we
think of additional benefits that we cannot obtain without
incompatibilities, then we can consider that situation when it arises.
In the meantime, there's no need to go looking for reasons to break
stuff that works in existing releases.

 Agreed.

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