Nico Sabbi <nsabbi(at)officinedigitali(dot)it> writes:
> i can't believe my eyes. Why on earth I can't drop a user without
> previously revoking his privileges?
Yeah, it's a known limitation. The reason it's not implemented is that
some of the privileges may be in other databases besides the particular
one you're connected to, and the backend hasn't got any way to get at
those databases to remove the entries.
Maybe someday it'll get fixed, but don't hold your breath.
regards, tom lane