查询oracle被锁的表及其如何释放

查询数据库中哪些表被锁定的sql语句

SELECT object_name, machine, s.sid, s.serial#
FROM gv$locked_object l, dba_objects o, gv$session s
WHERE l.object_id = o.object_id
AND l.session_id = s.sid;

 --释放SESSION SQL:
--alter system kill session 'sid, serial#';
ALTER system kill session '23, 1647';