I am not sure this is the same what I was thinking about. For example, in db2, connect privilege can be granted to a group and so is grant privilege as in
GRANT SELECT ON TABLE SCHEMA.TABLE TO GROUP ABC;
GRANT CONNECT ON DATABASE TO GROUP ABC
The "LOGIN" attribute for a Role is not inheritable and I do not imagine changing it to be is something the project can consider.
Every login user must have their own role in the database. These roles are separate from O/S users though "mappings" can be established between the two in pg_hba.conf.
