using ROLE system

Hi All,

I have a database where I give priviledges solely by user membership in
permitted roles (groups).

It works flowlessly, but when I tried to assign CREATEUSER priviledge to
an administrator ROLE (just one database administrator, not the
postmaster), I have to explicitly "SET ROLE ADMIN" before an attempt to
"CREATE USER ...". I don't have to do that to access tables/ views/
sequences, the group priviledges work OK just from being a member of
relevant group without the necesity to set current_role explicitly.

Is this a feature or a bug? Why?

My PostgresQL is v8.1.4.

And on a similar token: "SELECT current_user" works, while "SELECT
current_database" doesn't; yet "SELECT current_user()" doesn't work,
while "SELECT current_database()" does. Is this a feature or a bug?
--
-R