flashback query实验（基于undo数据）

开启闪回：http://blog.csdn.net/rlhua/article/details/11934831

误操作DML语句，刚刚发生，undo没有被覆盖

1、查询原数据

11:52:06 scott@TEST0910> select count(*) from test10;

 

  COUNT(*)

----------

        14

 

11:52:06 这个时间点还有数据，稍后作为参考

2、误操作

11:52:19 scott@TEST0910> delete from test10;

 

14 rows deleted.

 

11:52:31 scott@TEST0910> commit;

 

Commit complete.

 

11:52:35 scott@TEST0910> select count(*) from test10;

 

  COUNT(*)

----------

         0

3、使用闪回查询

11:54:25 scott@TEST0910> select * from test10 as of timestamp to_timestamp('2013-09-23 11:52:06','yyyy-mm-dd hh24:mi:ss');

 

     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO

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

      7369 SMITH      CLERK           7902 17-DEC-80        800                    20

      7499 ALLEN      SALESMAN        7698 20-FEB-81       1600        300         30

      7521 WARD       SALESMAN        7698 22-FEB-81       1250        500         30

      7566 JONES      MANAGER         7839 02-APR-81       2975                    20

      7654 MARTIN     SALESMAN        7698 28-SEP-81       1250       1400         30

      7698 BLAKE      MANAGER         7839 01-MAY-81       2850                    30

      7782 CLARK      MANAGER         7839 09-JUN-81       2450                    10

      7788 SCOTT      ANALYST         7566 19-APR-87       3000                    20

      7839 KING       PRESIDENT            17-NOV-81       5000                    10

      7844 TURNER     SALESMAN        7698 08-SEP-81       1500          0         30

      7876 ADAMS      CLERK           7788 23-MAY-87       1100                    20

      7900 JAMES      CLERK           7698 03-DEC-81        950                    30

      7902 FORD       ANALYST         7566 03-DEC-81       3000                    20

      7934 MILLER     CLERK           7782 23-JAN-82       1300                    10

 

14 rows selected.

 

4、插入闪回查询的结果

11:54:44 scott@TEST0910> insert into test10 select * from test10 as of timestamp to_timestamp('2013-09-23 11:52:06','yyyy-mm-dd hh24:mi:ss');

 

14 rows created.

 

11:55:02 scott@TEST0910> commit;

 

Commit complete.

 

11:55:30 scott@TEST0910> select count(*) from test10;

 

  COUNT(*)

----------

        14