锁表，锁会话，杀会话

被锁表查询

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; 

被锁会话查询

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; 

如果要断开某个会话，执行

alter system kill session 'sid,serial#';