Oracle数据库常见的误操作恢复方法（上）

实验环境：Linux6.4 + Oracle 11g

面向读者：Oracle开发维护人员

概要：

1.误操作drop了emp表

2.误操作delete了emp表

3.误操作delete了emp表的部分记录

4.误操作truncate了emp表

5.误操作带有purge选项drop了表

本文以Oracle自带的scott用户进行演示：

首先逻辑备份导出scott的对象数据

$ exp scott/tiger file='/u01/app/backup/scott.dmp' log='/u01/app/backup/scott.log' owner=scott;

1.误操作drop了emp表

利用表级闪回恢复，只要回收站中有就可以恢复。

SQL> drop table emp;

Table dropped.

闪回恢复

SQL> flashback table emp to before drop;

Flashback complete.

闪回回来的表如果之前有主键和索引，对应的名字会变成一串字符，虽然不影响使用，但为了规范管理，建议将它们重命名为之前的名字

重命名索引名称：

SQL> alter index  "BIN$ESbzggEjPKfgU58JqMDOTQ==$1" rename to PK_EMP;

Index altered

重命名主键约束名称：

SQL> alter table emp rename constraint "BIN$ESbzggEiPKfgU58JqMDOTQ==$1" to PK_EMP;

Table altered

若闪回表时，数据库已存在同名表，可以在闪回时指定新的表名：

SQL>  flashback table emp to before drop rename to emp1;

Flashback complete.

2.误操作delete了emp表

利用闪回查询结果恢复，只要undo表空间中还有误操作时间前的数据。

SQL> delete from emp;

14 rows deleted.

SQL> commit;

Commit complete.

SQL> select * from emp;

no rows selected

SQL> select * from emp as of timestamp to_timestamp('2015-03-13 15:00:00','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.

确定查询结果是要恢复的数据后，可以直接插入到emp表。

SQL> insert into emp select * from emp as of timestamp to_timestamp('2015-03-13 15:00:00','yyyy-mm-dd hh24:mi:ss');  

14 rows created.

SQL> commit;

Commit complete.

3.误操作delete了emp表的部分记录

利用闪回查询结果恢复，只要undo表空间中还有误操作时间前的数据，跟第二种场景一样，只是多了条件限定。

SQL> delete from emp where sal <2000;

8 rows deleted.

SQL> commit;

Commit complete.

SQL> select * from emp;

     EMPNO ENAME      JOB              MGR HIREDATE            SAL       COMM     DEPTNO

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

      7566 JONES      MANAGER         7839 02-APR-81          2975                    20

      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

      7902 FORD       ANALYST         7566 03-DEC-81          3000                    20

6 rows selected.

SQL>  select * from emp as of timestamp to_timestamp('2015-03-13 15:00:00','yyyy-mm-dd hh24:mi:ss') where sal <2000;

     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

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

      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

      7934 MILLER     CLERK           7782 23-JAN-82          1300                    10

8 rows selected.

确定查询结果是要恢复的数据后，可以直接插入到emp表。

SQL> insert into emp select * from emp as of timestamp to_timestamp('2015-03-13 15:00:00','yyyy-mm-dd hh24:mi:ss') where sal <2000;

8 rows created.

SQL> commit;

Commit complete.

4.误操作truncate了emp表

SQL> truncate table emp;

Table truncated.

这时由于表定义已经改变，无法查到表的历史数据了

SQL> select * from emp as of timestamp to_timestamp('2015-03-13 15:00:00','yyyy-mm-dd hh24:mi:ss');

select * from emp as of timestamp to_timestamp('2015-03-13 15:00:00','yyyy-mm-dd hh24:mi:ss')

              *

ERROR at line 1:

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

只能通过之前的备份恢复了，当然，只能恢复到exp导出时的状态。

$ imp scott/tiger file='/u01/app/backup/scott.dmp' log='/u01/app/backup/restore_emp.log' tables=emp ignore=y

Import: Release 11.2.0.4. - Production on Fri Mar  :: 

Copyright (c) , , Oracle and/or its affiliates.  All rights reserved. 

Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4. - 64bit Production

With the Partitioning, Automatic Storage Management, OLAP, Data Mining

and Real Application Testing options

Export file created by EXPORT:V11.02.00 via conventional path

import done in ZHS16GBK character set and AL16UTF16 NCHAR character set

. importing SCOTT's objects into SCOTT

. importing SCOTT's objects into SCOTT

. . importing table                          "EMP"          rows imported

About to enable constraints...

Import terminated successfully without warnings.

验证数据已经成功恢复

SQL> select count(1) from emp;

  COUNT(1)

----------

        14

5.误操作带有purge选项drop了表

SQL> drop table emp purge;

Table dropped.

由于purge选项的drop不进入回收站，闪回表不再可用。

SQL> flashback table emp to before drop;

flashback table emp to before drop

*

ERROR at line 1:

ORA-38305: object not in RECYCLE BIN

此时只能通过之前的备份恢复，跟第四种情形恢复方法一样，不再赘述。