"Mihai Gheorghiu" <tanethq(at)earthlink(dot)net> writes:
> It is possible that a user is a member of more than one group.
> Do this user's privileges AND or OR the privileges of each of the two
> groups?
OR. A user's privileges are always the union of what he has personally
and what he has via any group. See aclcheck() in
src/backend/catalog/aclchk.c: it keeps looking for any way to grant
permission.
regards, tom lane