先查询那些表被锁定了

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;

查询出被锁定的表的 sid 和serial# 然后kill

select b.username,b.sid,b.serial#,logon_time 
from v$locked_object a,v$session b
where a.session_id = b.sid and sid in(
select a.SESSION_ID
from v$locked_object a,dba_objects b
where b.object_id = a.object_id) order by b.logon_time

解锁

alter system kill session '589,2693' immediate;（589 是sid,2693是serial）

另外作此操作的必须要有数据库管理的权限否则无法解锁。