mkresse@slyde.in-berlin.de writes:
> Now, with Postgres 7.0 RC1, when some user (not the owner of the
> db, of course) tries to update, change or insert anything into
> choice, he gets an error message that says 'Permission denied' for
> table users.
IIRC this is a known bug in RC1 (permissions not handled correctly
for foreign key references). Have you tried it in 7.0 final?
regards, tom lane