Hi,
On 2019-08-02 18:47:07 -0400, Tom Lane wrote:
> Stephen Frost <sfrost@snowman.net> writes:
> > I disagree that this should only be addressed in alter system, as I’ve said
> > before and as others have agreed with. Having one set of code that can be
> > used to update parameters in the auto.conf and then have that be used by
> > pg_basebackup, alter system, and external tools, is the right approach.
>
> I don't find that to be necessary or even desirable. Many (most?) of the
> situations where this would be important wouldn't have access to a running
> backend, and maybe not to any PG code at all --- what if your tool isn't
> written in C?
I think a commandline tool to perform the equivalent of ALTER SYSTEM on
a shutdown cluster would be a great tool. It's easy enough to add
something with broken syntax, and further down the road such a tool
could not only ensure the syntax is correct, but also validate
individual settings as much as possible (obviously there's some hairy
issues here).
Quite possibly the most realistic way to implement something like that
would be a postgres commandline switch, which'd start up far enough to
perform GUC checks and execute AlterSystem(), and then shut down
again. We already have -C, I think such an option could reasonably be
implemented alongside it.
Obviously this is widely out of scope for v12.
Greetings,
Andres Freund