oracle 9i使用闪回查询恢复数据库误删问题

ALTER TABLE tablename ENABLE row movement ;
flashback table tablename to timestamp to_timestamp('2012-09-13 13:00:00','yyyy-mm-dd hh24:mi:ss');

 $ sqlplus eygle/eygle
SQLPlus: 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
SQL>select count() from t1;
  COUNT()
----------
    9318

SQL>delete from t1;
9318 rows deleted.
SQL>mit;
Commit plete.
SQL>select count() from t1;
  COUNT()
----------
     0

SQL>select dbms_flashback.get_system_change_number from dual;
GET_SYSTEM_CHANGE_NUMBER
------------------------
         10671006
SQL>select count() from t1 as of s 10671000;
  COUNT()
----------
     0
SQL>select count() from t1 as of s 10670000;
  COUNT()
----------
    9318

SQL>insert into t1 select  from t1 as of s 10670000;
9318 rows created.
SQL>mit;
Commit plete.
SQL>select count() from t1;
  COUNT()
----------
    9318

. select  from t_viradsl t     //查询t_viradsl中所有的数据，可以看到三条数据
 . delete t_viradsl           //删除t_viradsl中所有的数据，三条数据消失
 . select  from t_viradsl t     //无数据。
 . insert into t_viradsl select  from t_viradsl as of timestamp to_Date('-- ::', 'yyyy-mm-dd hh:mi:ss')       //已将误删除数据插入表中
 . select  from t_viradsl t     //又会看到三条数据。

select  from t_viradsl2 as of timestamp to_Date('2011-01-19 15:28:00', 'yyyy-mm-dd hh24:mi:ss')