Re: GUC flags

On Thu, Dec 09, 2021 at 09:53:23AM -0600, Justin Pryzby wrote:
> On Thu, Dec 09, 2021 at 05:17:54PM +0900, Michael Paquier wrote:
> > On Wed, Dec 08, 2021 at 01:23:51PM +0100, Peter Eisentraut wrote:
> > > I wasn't really aware of this script either. But I think it's a good idea
> > > to have it. But only if it's run automatically as part of a test suite run.
> >
> > Okay. If we do that, I am wondering whether it would be better to
> > rewrite this script in perl then, so as there is no need to worry
> > about the compatibility of grep. And also, it would make sense to
> > return a non-zero exit code if an incompatibility is found for the
> > automation part.
>
> One option is to expose the GUC flags in pg_settings, so this can all be done
> in SQL regression tests.
>
> Maybe the flags should be text strings, so it's a nicer user-facing interface.
> But then the field would be pretty wide, even though we're only adding it for
> regression tests. The only other alternative I can think of is to make a
> sql-callable function like pg_get_guc_flags(text guc).

Rebased on cab5b9ab2c066ba904f13de2681872dcda31e207.

And added 0003, which changes to instead exposes the flags as a function, to
avoid changing pg_settings and exposing internally-defined integer flags in
that somewhat prominent view.

--
Justin