Re: Allow ALTER SYSTEM SET on unrecognized custom GUCs

Thanks for the answer. The code looks good to me.

Thanks,
Shihao

On Thu, Oct 19, 2023 at 12:00 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> shihao zhong <zhong950419(at)gmail(dot)com> writes:
> > I do like the idea that we should keep the set and the altar system with
> > the same behavior. But one thing I am worried about is the typo detected
> > here because I usually make that type of mistake myself. I believe we
> > should have an extra log to explicitly tell the user this is a `custom
> > variable` guc.
>
> I don't think there's any chance of getting away with that. As noted
> upthread, a lot of people use placeholder GUCs as a substitute for a
> proper session-variable feature. If we ever get real session variables,
> we could start to nudge people away from using placeholders; but right
> now too many people would complain about the noise of a warning.
>
> > Btw, another aspect I want to better understand is if the superuser
> session
> > called pg_reload_conf with custom variables, does that mean these custom
> > variables will override the other active transaction's SET command?
>
> No, a per-session SET will override a value coming from the config file.
> That's independent of whether it's a regular or custom GUC.
>
> regards, tom lane
>