1. 查看被锁的表

select b.owner, b.object_name, a.session_id, a.locked_mode
  from v$locked_object a, dba_objects b
 where b.object_id = a.object_id; -- 972

2. 查看造成锁表的session

select b.username, b.sid, b.serial#, logon_time
  from v$locked_object a, v$session b
 where a.session_id = b.sid
 order by b.logon_time; -- 972,53059

3. 删除造成锁表的session

alert system kill session 'sid,serial'    
--- sid ： 是 2 中查询得到的sid   serial ：是2中查询得到的serial