Query : To find DataBase Locking

SELECT o.object_name,
l.oracle_username,
l.os_user_name,
s.machine,
s.program,
DECODE(l.locked_mode,0,'None',1,'NULL',2,'Row-S(SS)',3,'Row-X(SX)',
4,'Share',5,'S/Row-X(SSX)',6,'Exclusive(X)') locked_mode,
s.sid,
s.serial#
FROM all_objects o,v$locked_object l,v$session s
WHERE l.session_id = s.sid
AND l.object_id=o.object_id