Re: no mention of GRANT USAGE in postgres_fdw docs

PG Doc comments form <noreply(at)postgresql(dot)org> writes:
> The documentation page for postgres_fdw
> <https://www.postgresql.org/docs/current/postgres-fdw.html> gives a nice
> step by step on what's needed to configure a FOREIGN SERVER. However, one
> crucial step is missed, and that is that you need to issue GRANT USAGE ON
> FOREIGN SERVER before you can successfully run step 4, IMPORT FOREIGN
> SCHEMA.

That paragraph links to the IMPORT FOREIGN SCHEMA reference page,
which says

To use IMPORT FOREIGN SCHEMA, the user must have USAGE privilege on
the foreign server, as well as CREATE privilege on the target schema.

I'm not clear why we should duplicate that information here, especially
when we're not duplicating any of the other essential information about
how to use IMPORT FOREIGN SCHEMA. Nor does this summary mention the
privilege requirements for any of the other commands it suggests using.

Is there some reason why this was particularly hard to discover?
I'd have expected that you got a reasonably clear permissions-
failure error from the IMPORT. If you didn't, maybe there's an
opportunity to improve that.

regards, tom lane