1.查看哪个表被锁:

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;

2.查看被锁表的sid 和serial# :

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;

3.执行下面的语句:

alter system kill session 'sid,serial#';