Oracle数据恢复--flashback

对于表的恢复

db_flashback_retention_target参数决定删除表以及表中数据保留时间

sql>conn / as sysdba

Connected.

sql>alter system set db_flashback_retention_target=3600;

System altered.

sql>

确认处于归档模式

sql>select dbid,name,log_mode from v$database;

DBID NAME LOG_MODE

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

1573521836 FENGZIARCHIVELOG

sql>

查询所有表删除其中一个表

sql>conn u2/u2

sql>select * from tab;

TNAME TABTYPE CLUSTERID

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

BB2 TABLE

EMPTY TABLE

TEMP TABLE

sql>drop table bb2;

Table dropped.

查询回收站

sql>show recyclebin

ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME

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

BB2 BIN$98CBLGsSLR/gQKjACjgQQQ==$0 TABLE 2014-04-24:09:09:44

恢复表

sql>flashback table bb2 to before drop;

Flashback complete.

sql>select * from bb2;

ID

----------

1

12 rows selected.

如果删除期间创建了原表名的表在删除在回收站会有两个选项

sql>create table bb2 as select * from temp;

Table created.

BB2 BIN$98Cx0ajtOxDgQKjACjgQYg==$0 TABLE 2014-04-24:09:23:20

BB2 BIN$98Cx0ajuOxDgQKjACjgQYg==$0 TABLE 2014-04-24:09:24:59

sql>

如果还使用BB2名称恢复表的话，得到的表为最后一次删除的表内容。

想要恢复之前的表需要

BB2BIN$98Cx0ajtOxDgQKjACjgQYg==$0TABLE2014-04-24:09:23:20

sql> flashback table "BIN$98Cx0ajtOxDgQKjACjgQYg==$0" to before drop;

sql>

对于表中行的恢复

这种方法有点时候是不实用的

sql>select to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') from dual;

TO_CHAR(SYSDATE,'YY

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

2014-04-24 09:38:05

sql>update bb2 set id=id+1 where id=1;

12 rows updated.

sql>commit;

Commit complete.

sql>alter table bb2 enable row movement;

Table altered.

sql>flashback table bb2 to timestamp to_timestamp('2014-04-24 09:38:05','yyyy-mm-dd hh24:mi:ss');

sql>alter table bb2 disable row movement;

sql>

比较实用的方法 2

14 rows selected.

2014-04-24 09:55:07

sql>delete bb2 where id=2;

2 rows deleted.

sql>select * from bb2 as of timestamp to_timestamp('2014-04-24 09:55:07','yyyy-mm-dd hh24:mi:ss')where id=2;

sql>select * from bb2 where id=2;

no rows selected