"David G. Johnston" <david.g.johnston@gmail.com> writes:
> I've seen and can work with various work-arounds but it seems odd that
> pg_settings doesn't show these custom GUCs.
Because we don't know what type they should be.
If we're ever to support custom GUCs properly, rather than as a hack that
accidentally sorta works, there needs to be a way to declare them and
establish their properties; whereupon there would be info for pg_settings
to display.
> Is there a simple way to read the value without receiving an error if the
> value is missing?
See 10fb48d66, which I don't particularly approve of because it piled
another hack on top of that mess without doing a thing to make it cleaner.
regards, tom lane