eygle Eygle.
Backup&Recovery 2005-03-30

使用Oracle10g的Flashback Query进行数据闪回

eygle 2005-03-30 09:00
modb.pro
Oracle10g对于闪回查询进行了增强，支持更简单的SQL操作，允许对误删除、误更新等DML操作进行闪回。
看一下以下测试:
1.原表记录 


$ sqlplus eygle/eygle

SQL*Plus: Release 10.1.0.2.0 - Production on Wed Mar 30 08:52:04 2005

Copyright (c) 1982, 2004, Oracle.  All rights reserved.


Connected to:
Oracle Database 10g Enterprise Edition Release 10.1.0.2.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options

EYGLE  on 30-MAR-05 >select count(*) from t1;

  COUNT(*)
----------
      9318

2.误删除所有记录
并且提交更改。


EYGLE  on 30-MAR-05 >delete from t1;

9318 rows deleted.

EYGLE  on 30-MAR-05 >commit;

Commit complete.

EYGLE  on 30-MAR-05 >select count(*) from t1;

  COUNT(*)
----------
         0

3.获得当前SCN
如果能够确切知道删除之前SCN最好，如果不知道，可以进行闪回查询尝试.


EYGLE  on 30-MAR-05 >select dbms_flashback.get_system_change_number from dual;

GET_SYSTEM_CHANGE_NUMBER
------------------------
                10671006

EYGLE  on 30-MAR-05 >select count(*) from t1 as of scn 10671000;

  COUNT(*)
----------
         0

EYGLE  on 30-MAR-05 >select count(*) from t1 as of scn 10670000;

  COUNT(*)
----------
      9318

我们看到在SCN=10670000时，数据都在。
4.恢复数据.


EYGLE  on 30-MAR-05 >insert into t1 select * from t1 as of scn 10670000;

9318 rows created.

EYGLE  on 30-MAR-05 >commit;

Commit complete.

EYGLE  on 30-MAR-05 >select count(*) from t1;

  COUNT(*)
----------
      9318

EYGLE  on 30-MAR-05 >


历史上的今天
By eygle 2005-03-30 09:00 评论 (1)
eygle
eygle

前Oracle ACE Director，云和恩墨创始人。技术为骨，历史为脉，人文为魂。

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1 Comment

Steven | September 1, 2006 8:18 PM

关于select * from table as of scn *******这个功能在9i也已经有了阿.