网上有很多关于数据回复的文章,这里整理一篇供大家参考,希望能帮助的大家!
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好了,言归正传!如果你在工作中误删除了一部分重要的数据,并且已经提交,如果你需要回复这些数据,你可以登陆到数据库上仔细查看,是Oracle9iR2的话,你可以首先尝试使用flashback query闪回数据。
◆第一步: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.dbf 12929941968 12929942881 2005-06-22 14:38:28
- /mwarch/oracle/1_52414.dbf 12929942881 12929943706 2005-06-22 14:38:32
- /mwarch/oracle/1_52415.dbf 12929943706 12929944623 2005-06-22 14:38:35
- /mwarch/oracle/1_52416.dbf 12929944623 12929945392 2005-06-22 14:38:38
- /mwarch/oracle/1_52417.dbf 12929945392 12929945888 2005-06-22 14:38:41
- /mwarch/oracle/1_52418.dbf 12929945888 12929945965 2005-06-22 14:38:44
- /mwarch/oracle/1_52419.dbf 12929945965 12929948945 2005-06-22 14:38:45
- /mwarch/oracle/1_52420.dbf 12929948945 12929949904 2005-06-22 14:46:05
- /mwarch/oracle/1_52421.dbf 12929949904 12929950854 2005-06-22 14:46:08
- /mwarch/oracle/1_52422.dbf 12929950854 12929951751 2005-06-22 14:46:11
- /mwarch/oracle/1_52423.dbf 12929951751 12929952587 2005-06-22 14:46:14
- ...................
- /mwarch/oracle/1_52498.dbf 12930138975 12930139212 2005-06-22 15:55:57
- /mwarch/oracle/1_52499.dbf 12930139212 12930139446 2005-06-22 15:55:59
- /mwarch/oracle/1_52500.dbf 12930139446 12930139682 2005-06-22 15:56:00
- NAME FSCN NSCN FIRST_TIME
- ------------------------- ------------- -----------
- /mwarch/oracle/1_52501.dbf 12930139682 12930139915 2005-06-22 15:56:02
- /mwarch/oracle/1_52502.dbf 12930139915 12930140149 2005-06-22 15:56:03
- /mwarch/oracle/1_52503.dbf 12930140149 12930140379 2005-06-22 15:56:05
- /mwarch/oracle/1_52504.dbf 12930140379 12930140610 2005-06-22 15:56:05
- /mwarch/oracle/1_52505.dbf 12930140610 12930140845 2005-06-22 15:56:07
- 14811 rows selected.
◆此时的SCN为:
- SQL> select dbms_flashback.
- get_system_change_number fscn from dual;
- FSCN
- --------------------
- 12930142214
◆此时使用应用用户尝试闪回
- SQL> connect username/password
- Connected.
◆现有的数据
- 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.
◆此处选择SCN向前恢复
- 以下为引用的内容:
- SQL> select count(*) from hs_passport as of scn 12929970422;
- COUNT(*)
- ----------
- 861686
◆尝试多个SCN,获取最佳值(注释:如果可以得知具体时间,那样则可以获得准确的数据闪回)
- 以下为引用的内容:
- 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
◆注意:最后选择恢复到SCN为12929941968的时间点
- 以下为引用的内容:
- SQL>
- insert into hs_passport_recov
- select * from hs_passport as of scn 12929941968;
- 861684 rows created.
- SQL> commit;
- Commit complete.
注释:至此,则可以满足需要,找回误删除的部分数据,闪回恢复成功。