Using role priviledges for pg_dump

Given:

CREATE ROLE joe WITH LOGIN;
CREATE ROLE dumpable;
ALTER GROUP dumpable ADD USER joe;

If I have a database called db1 to which the role dumpable has enough
permissions to do a full pg_dump, but he user joe does not, how can
joe do a pg_dump?  Is it possible?

--
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/

wmoran@collaborativefusion.com
Phone: 412-422-3463x4023