The following query lists all roles and their members:
SELECT CAST(rolename AS CHAR(15)), CAST(grantee AS CHAR(20)), CAST(grantor AS CHAR(20)), whengranted FROM DBC.RoleMembersV ORDER BY 1,2;
Result:
RoleName Grantee Grantor WhenGranted ---------- -------- -------- -------------------- role_a user_1 DBA 97-10-15 14:32:59 role_a user_2 DBA 97-10-15 11:00:01 role_b user_1 SysFe 98-04-24 09:10:15 . . . . . . . . . . . .