select *
from session_privs;
select * from user_sys_privs
where username='C##KING4';
select username
from dba_users
where username like 'C##%' ;
create user c##allen
identified by tiger;
grant 시스템권한이름
to c##allen 유저;
revoke select on emp from c##king3
grant connect to c##jane;
grant c##manager to c##martin;
drop role c##manager;