View User Rights

1. View All Users:
SELECT * from Dba_users;
SELECT * from All_users;

2. View the currently logged-on User:
SELECT * from User_users;

3. View system permissions for all users:
SELECT * from Dba_sys_privs;

4. View the system permissions that the currently logged-on user has
SELECT * from User_sys_privs;

5. View the system permissions for the roles and roles owned by the currently logged-on user

SELECT * from Role_sys_privs;

6. View all user-owned object permissions:
SELECT * from Dba_tab_privs;
SELECT * from All_tab_privs;

7. View the object permissions that the currently logged-on user has:
SELECT * from User_tab_privs;

8. View all roles:
SELECT * from Dba_roles;

9. View the roles of all users

SELECT * from Dba_role_privs;

10. View the roles owned by the currently logged-on User:
SELECT * from User_role_privs;

11. See which users have SYSDBA or sysoper system privileges

SELECT * FROM V$pwfile_users

12. View all system permissions:

Select name from Sys.system_privilege_map

13. View system permissions for the system permissions that a user has and the roles they have:

SELECT privilege
From Dba_sys_privs
WHERE grantee = ' APPS '
UNION
SELECT privilege
From Dba_sys_privs
WHERE grantee in
(SELECT granted_role from dba_role_privs WHERE grantee = ' APPS ');