Re: SHOW ALL doesn't actually SHOW ALL

David Fetter <david@fetter.org> writes:
> I've noticed that neither SHOW ALL nor SELECT ... FROM pg_settings
> shows the value of custom GUCs, even though SHOW will do so for any
> given one.

Yeah, that's intentional, because what the code is designed to do is
allow GUC values for a user-written module to be specified before the
user-written module has been loaded.  It's expecting the user-written
code to come along and issue a DefineCustomXXXVariable call so that
it will know how (or whether) to display the variable.

This ties back into previous discussions about how using this facility
for random user-set values is an abuse, and we ought to instead provide
some way of explicitly declaring user variables.
        regards, tom lane