锁表怎么解决oracle_锁表了怎么解锁

oracle 表锁住了什么原因

在对指定表做append操作,其他再做truncate时候,会产生锁表,如下验证步骤,

①.、创建测试表,

select b.object_name, t.*

from v$locked_object t, user_objects b

where t.object_id = b.object_id

oracle如何解锁表

一些ORACLE中的进程被杀掉后,状态被置为"killed",但是锁定的资源很长时间不释放,有时实在没办法,只好重启数据库.现在提供一种方法解决这种问题,那就是在ORACLE中杀不掉的,在OS一级再杀.

①下面的语句用来查询哪些对象被锁：

select object_name,machine,s.sid,s.serial#

from v$locked_object l,dba_objects o ,v$session s

where l.object_id　=　o.object_id and l.session_id=s.sid;

【注】以上两步,可以通过Oracle的管理控制台来执行.

select spid, osuser, s.program

from v$session s,v$process p

①.)在unix上,用root身份执行命令:

orakill sid thread

其中：

sid：表示要杀死的进程属于的实例名

模拟oracle数据库update锁表现象及处理办法

Session1创建测试表：

Table created.

SQL desc test;

Name Null? Type

----------------------------------------- -------- ----------------------------

ID NOT NULL NUMBER(10)

SQL insert into test values(001,'tom');

①. row created.

查看test表信息

SQL update test set name='xue' where name='joy';

①. row updated.

SQL commit;

Commit complete.

SQL select * from test updata;

ID NAME

---------- --------------------

①. tom

SQL select * from test；

update模拟锁表

SQL update test set name='da' where name='tom';

注：不提交

查看哪个表被锁

SQL 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;

OWNER

------------------------------

OBJECT_NAME

--------------------------------------------------------------------------------

SESSION_ID LOCKED_MODE

---------- -----------

SYS

TEST

查看是哪个session引起的

SQL 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;

USERNAME SID SERIAL# LOGON_TIM

------------------------------ ---------- ---------- ---------

杀掉对应进程

System altered.

no rows selected

session 1查询：

SQL select * from test;

select * from test

*

ERROR at line 1:

重新连接SQL

Connected to:

With the Partitioning, OLAP, Data Mining and Real Application Testing options