使用Oracle9i的新特性Flashback Query恢复误删除数据

王朝oracle·作者佚名  2008-05-31
窄屏简体版  字體: |||超大  

下午接到研发工程师的电话,说误删除了部分重要数据,并且已经提交,需要恢复。

登陆到数据库上查看,由于是Oracle9iR2,首先尝试使用flashback query闪回数据。

首先确认数据库的SCN变化:

SQL col fscn for 9999999999999999999

SQL col nscn for 9999999999999999999

SQL select name,FIRST_CHANGE# fscn,NEXT_CHANGE# nscn,FIRST_TIME from v$archived_log;

...................

NAME FSCN NSCN FIRST_TIME

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

/mwarch/oracle/1_52413.dbf1292994196812929942881 2005-06-22 14:38:28

/mwarch/oracle/1_52414.dbf1292994288112929943706 2005-06-22 14:38:32

/mwarch/oracle/1_52415.dbf1292994370612929944623 2005-06-22 14:38:35

/mwarch/oracle/1_52416.dbf1292994462312929945392 2005-06-22 14:38:38

/mwarch/oracle/1_52417.dbf1292994539212929945888 2005-06-22 14:38:41

/mwarch/oracle/1_52418.dbf1292994588812929945965 2005-06-22 14:38:44

/mwarch/oracle/1_52419.dbf1292994596512929948945 2005-06-22 14:38:45

/mwarch/oracle/1_52420.dbf1292994894512929949904 2005-06-22 14:46:05

/mwarch/oracle/1_52421.dbf1292994990412929950854 2005-06-22 14:46:08

/mwarch/oracle/1_52422.dbf1292995085412929951751 2005-06-22 14:46:11

/mwarch/oracle/1_52423.dbf1292995175112929952587 2005-06-22 14:46:14

...................

/mwarch/oracle/1_52498.dbf1293013897512930139212 2005-06-22 15:55:57

/mwarch/oracle/1_52499.dbf1293013921212930139446 2005-06-22 15:55:59

/mwarch/oracle/1_52500.dbf1293013944612930139682 2005-06-22 15:56:00

NAME FSCN NSCN FIRST_TIME

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

/mwarch/oracle/1_52501.dbf1293013968212930139915 2005-06-22 15:56:02

/mwarch/oracle/1_52502.dbf1293013991512930140149 2005-06-22 15:56:03

/mwarch/oracle/1_52503.dbf1293014014912930140379 2005-06-22 15:56:05

/mwarch/oracle/1_52504.dbf1293014037912930140610 2005-06-22 15:56:05

/mwarch/oracle/1_52505.dbf1293014061012930140845 2005-06-22 15:56:07

14811 rows selected.

当前的SCN为:

SQL select dbms_flashback.get_system_change_number fscn from dual;

FSCN

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

12930142214

使用应用用户尝试闪回

SQL connect username/passWord

Connected.

现有数据:

SQL select count(*) from hs_passport;

COUNT(*)

----------

851998

创建恢复表

SQL create table hs_passport_recov as select * from hs_passport where 1=0;

Table created.

选择SCN向前恢复

SQL select count(*) from hs_passport as of scn 12929970422;

COUNT(*)

----------

861686

尝试多个SCN,获取最佳值(假如能得知具体时间,那么可以获得准确的数据闪回)

SQL select count(*) from hs_passport as of scn &scn;

Enter value for scn: 12929941968

old 1: select count(*) from hs_passport as of scn &scn

new 1: select count(*) from hs_passport as of scn 12929941968

COUNT(*)

----------

861684

SQL /

Enter value for scn: 12927633776

old 1: select count(*) from hs_passport as of scn &scn

new 1: select count(*) from hs_passport as of scn 12927633776

select count(*) from hs_passport as of scn 12927633776

*

ERROR at line 1:

ORA-01466: unable to read data - table definition has changed

SQL /

Enter value for scn: 12929928784

old 1: select count(*) from hs_passport as of scn &scn

new 1: select count(*) from hs_passport as of scn 12929928784

COUNT(*)

----------

825110

SQL /

Enter value for scn: 12928000000

old 1: select count(*) from hs_passport as of scn &scn

new 1: select count(*) from hs_passport as of scn 12928000000

select count(*) from hs_passport as of scn 12928000000

*

ERROR at line 1:

ORA-01466: unable to read data - table definition has changed

最后选择恢复到SCN为12929941968的时间点

SQL insert into hs_passport_recov select * from hs_passport as of scn 12929941968;

861684 rows created.

SQL commit;

Commit complete.

研发人员确认,已经可以满足需要,找回误删除部分数据,至此闪回恢复成功完成。

 
 
 
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