使用Oracle10g的Flashback Query进行数据闪回

核心提示：Oracle10g对于闪回查询进行了增强，支持更简单的SQL操作，使用Oracle10g的Flashback Query进行数据闪回，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/eygleSQL*Plus: Release 10.1.0.2.0 - Produc

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(*)
----------
03.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 >