Re: catalog access with reset GUCs during parallel worker startup

On Wed, Feb 9, 2022 at 7:33 PM Andres Freund <andres(at)anarazel(dot)de> wrote:
> > Can we arrange to absorb the leader's values before starting the
> > worker's transaction, instead of inside it?
>
> I assume Robert did it this way for a reason? It'd not be surprising if there
> were a bunch of extensions assuming its safe to do catalog accesses if
> IsUnderPostmaster or such :(

I remember trying that, and if I remember correctly, it broke with
core GUCs, without any need for extensions in the picture. I don't
remember the details too well, unfortunately, but I think it had to do
with the behavior of some of the check and/or assign hooks.

It's probably time to try it again, because (a) maybe things are
different now, or (b) maybe I did it wrong, and in any event (c) I
can't really remember why it didn't work and we probably want to know
that.

--
Robert Haas
EDB: http://www.enterprisedb.com