ORACLE查询数据库是否存在锁&解锁

/*查看数据库是否有锁*/
select b.owner,b.object_name,l.session_id,l.locked_mode
from v$locked_object l, dba_objects b
where b.object_id=l.object_id ;

select t2.username,t2.sid,t2.serial#,t2.logon_time
from v$locked_object t1,v$session t2
where t1.session_id=t2.sid order by t2.logon_time;

/*解锁*/
alter system kill session '871,50131';    --'871,50131'为第二句SQL的 sid和serial#