1.开一个会话session1

sql>select sid from v$mystat where rownum=1;

SID

158

sql>create table t(x int primary key);

table created

sql>insert into t values(1);

commit;

sql>update t1 set t=10 where x=1;

2.再开一个会话

sql>select sid from v$mystat where rowunm=1;

SID

157

sql>update t1 se x=10 where x=1;

这个时候session2被session1锁住

3、执行以下语句查看是哪个进程和序列锁住了表

select sess.sid,

sess.serial#,

lo.oracle_username,

lo.os_user_name,

ao.object_name,

lo.locked_mode

from v$locked_object lo,

dba_objects ao,

v$session sess

where ao.object_id = lo.object_id and lo.session_id = sess.sid

4、执行下面的语句，将改锁表的进程和序列杀掉了

alter system kill session '1020,38953' --(1020，就是执行第一步语句得到的sid字段值，38953就是serial#字段值)

参考博文：http://www.cnblogs.com/srsee/archive/2013/05/10/infi0510_2.html