如何在其他Session跳过被锁定的记录

如何在其他Session跳过被锁定的记录
作者:eygle
出处:http://www.eygle.com/blog
日期:March 04, 2005
浏览次数:187
本文链接:http://www.eygle.com/archives/2005/03/eciouaeeeusessi.html

? 如何重建UNDO TABLESPACE | Blog首页 | CSDN的Blog,我们最需要什么? ?

--------------------------------------------------------------------------------
有人问到这样的问题:如果一个用户对记录加锁，如何使其他用户看不到这条记录。
此前并未注意到这样一个用法（需要8.1.7.4.16以上的版本支持）:

[oracle@jumper oracle]$ sqlplus scott/tiger

SQL*Plus: Release 9.2.0.4.0 - Production on Fri Mar 4 11:59:46 2005

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

SQL> select * from dept;

DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
33 ORACLE beijing
35 Oracle Beijing
36 Oracle Beijing
37 Oracle Beijing

8 rows selected.

SQL> select * from dept where deptno =10 for update;

DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK

SQL> !
[oracle@jumper oracle]$ sqlplus scott/tiger

SQL*Plus: Release 9.2.0.4.0 - Production on Fri Mar 4 12:00:14 2005

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

SQL> select * from dept for update skip locked;

DEPTNO DNAME LOC
---------- -------------- -------------
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
33 ORACLE beijing
35 Oracle Beijing
36 Oracle Beijing
37 Oracle Beijing

7 rows selected.

SQL>

存此备忘。