Oracle10g Flashback Query数据闪回

王朝oracle·作者佚名  2008-05-31
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Oracle10g通过Flashback Version Query提供查看对数据库事务级改变的方法.

当闪回事务处理查询与闪回版本查询同时使用时,我们可以轻易地从用户或者应用程序错误恢复。

以下是闪回版本查询的示例:

1.执行DML操作

EYGLE on 30-MAR-05 >create table t as select username,user_id from dba_users;

Table created.

EYGLE on 30-MAR-05 >select * from t;

USERNAME USER_ID

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

SYSTEM 5

SYS 0

TEST 25

EYGLE 26

SCOTT 29

DIP 19

TRANS 27

TEST1 28

OPERATOR 31

WMSYS 23

DBSNMP 22

USERNAME USER_ID

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

OUTLN 11

12 rows selected.

EYGLE on 30-MAR-05 >delete from t where username='OUTLN';

1 row deleted.

EYGLE on 30-MAR-05 >commit;

Commit complete.

EYGLE on 30-MAR-05 >delete from t where username='TEST1';

1 row deleted.

EYGLE on 30-MAR-05 >commit;

Commit complete.

EYGLE on 30-MAR-05 >select * from t;

USERNAME USER_ID

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

SYSTEM 5

SYS 0

TEST 25

EYGLE 26

SCOTT 29

DIP 19

TRANS 27

OPERATOR 31

WMSYS 23

DBSNMP 22

10 rows selected.

EYGLE on 30-MAR-05 >update t set user_id=1 where username='EYGLE';

1 row updated.

EYGLE on 30-MAR-05 >commit;

Commit complete.

EYGLE on 30-MAR-05 >delete from t where user_id >10;

7 rows deleted.

EYGLE on 30-MAR-05 >commit;

Commit complete.

EYGLE on 30-MAR-05 >select * from t;

USERNAME USER_ID

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

SYSTEM 5

SYS 0

EYGLE 1

EYGLE on 30-MAR-05 >insert into t values('PENNY',2);

1 row created.

EYGLE on 30-MAR-05 >commit;

Commit complete.

2.执行闪回版本查询

EYGLE on 30-MAR-05 >select versions_starttime, versions_endtime, versions_xid,

2 versions_operation, username,user_id

3 from t versions between timestamp minvalue and maxvalue

4 /

VERSIONS_STARTTIME VERSIONS_ENDTIME VERSIONS_XID V USERNAME USER_ID

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

30-MAR-05 09.34.49 AM 000A000B000000F1 D DBSNMP 22

30-MAR-05 09.34.49 AM 000A000B000000F1 D WMSYS 23

30-MAR-05 09.34.49 AM 000A000B000000F1 D OPERATOR 31

30-MAR-05 09.34.49 AM 000A000B000000F1 D TRANS 27

30-MAR-05 09.34.49 AM 000A000B000000F1 D DIP 19

30-MAR-05 09.34.49 AM 000A000B000000F1 D SCOTT 29

30-MAR-05 09.34.49 AM 000A000B000000F1 D TEST 25

30-MAR-05 09.34.15 AM 0001001900000F0F U EYGLE 1

30-MAR-05 09.33.51 AM 00080016000000EF D TEST1 28

30-MAR-05 09.33.23 AM 0004000A000005EF D OUTLN 11

SYSTEM 5

VERSIONS_STARTTIME VERSIONS_ENDTIME VERSIONS_XID V USERNAME USER_ID

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

SYS 0

30-MAR-05 09.34.49 AM TEST 25

30-MAR-05 09.34.15 AM EYGLE 26

30-MAR-05 09.34.49 AM SCOTT 29

30-MAR-05 09.34.49 AM DIP 19

30-MAR-05 09.34.49 AM TRANS 27

30-MAR-05 09.33.51 AM TEST1 28

30-MAR-05 09.34.49 AM OPERATOR 31

30-MAR-05 09.34.49 AM WMSYS 23

30-MAR-05 09.34.49 AM DBSNMP 22

30-MAR-05 09.33.23 AM OUTLN 11

VERSIONS_STARTTIME VERSIONS_ENDTIME VERSIONS_XID V USERNAME USER_ID

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

30-MAR-05 09.49.24 AM 00080006000000EF I PENNY 2

23 rows selected.

EYGLE on 30-MAR-05 >

我们可以看到,以上事务的时间以及数据更改。

 
 
 
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