转载出处:http://www.oracleblog.org/working-case/dba-always-bad-luck-with-careless-customer/
今晚接到老大的电话,泰国的客户不小心删除了一些表的数据,现在非常着急,需要恢复数据。其实DBA做的数据库备份,很大程度是是用于数据库crash掉的时候,恢复数据,而不是三天两头的因为客户误删了数据,而去做恢复。
看了客户的邮件,是有2个表的数据被误删除或者误插入或者误更新了。总之,操作过一大通,希望恢复到当天下午15:30的数据。上数据库去查了一下,用备份来恢复,似乎时间不够,尝试用户flashback query,发现已经回不去了:
2 AS OF TIMESTAMP TO_TIMESTAMP ( ' 2011-06-09 15:29:00 ' , ' YYYY-MM-DD HH24:MI:SS ' ) ;
SELECT count ( * ) from hr_ttm . TA_ABSDOCS
*
ERROR at line 1 :
ORA - 01555 : snapshot too old : rollback segment number 1 with name " _SYSSMU1$ "
too small
其他也没有更快的方法了,于是当下决定用logmnr挖数据,
由于数据库原来就没有配置utl_file_dir,因此还需要重启数据库使得该参数生效。一路做下来,大致算顺利,不过也遇到了不少小插曲。下面就是恢复的步骤:
一、备份原表
SELECT * from hr_ttm . TA_ABSDOCS ;
create table hr_ttm . TA_ABSDOC_20110610_0010 as
SELECT * from hr_ttm . TA_ABSDOC ;
二,根据客户要求,建立新用户,将恢复的数据导入到这2个表中:
grant connect , resource , dba to hr_ttm2 ;
三、把原表数据备份到新用户下,用于做回滚
SELECT * from hr_ttm . TA_ABSDOCS
create table hr_ttm2 . TA_ABSDOC as
SELECT * from hr_ttm . TA_ABSDOC
四、修改参数,用于挖日志,重启数据库
五、生成数据字典
做这一步之前注意需要修改LD_LIBRARY_PATH和LIBPATH,使得lib的变量在lib32前面。不然会有报错ORA-00600: internal error code, arguments: [unable to load XDB library], [], [], [], [], [], [], []
六、检查需要回滚的日志,客户要求回滚到6月9日15:30之前:
-rw-r----- 1 oracle oinstall 48868864 Jun 09 15:08 ARC0000025855_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 15:17 ARC0000025856_0666465023.0001
-rw-r----- 1 oracle oinstall 48910848 Jun 09 15:42 ARC0000025857_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 16:04 ARC0000025858_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 17:22 ARC0000025859_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 17:27 ARC0000025860_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 17:47 ARC0000025861_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 20:52 ARC0000025862_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 21:17 ARC0000025863_0666465023.0001
drwxr-xr-x 2 oracle oinstall 256 Jun 09 23:02 logmnr
-rw-r----- 1 oracle oinstall 48863744 Jun 09 23:07 ARC0000025864_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:28 ARC0000025865_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:29 ARC0000025866_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:29 ARC0000025867_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:29 ARC0000025868_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:29 ARC0000025869_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:30 ARC0000025870_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:30 ARC0000025871_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:30 ARC0000025872_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:31 ARC0000025873_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:31 ARC0000025874_0666465023.0001
-rw-r----- 1 oracle oinstall 48868864 Jun 09 23:31 ARC0000025875_0666465023.0001
七、添加归档日志
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025855_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025856_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025857_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025858_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025859_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025860_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025861_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025862_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025863_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025864_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025865_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025866_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025867_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025868_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025869_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025870_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025871_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025872_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025873_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025874_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
exec dbms_logmnr . add_logfile ( LogFileName => ' /prodlog/logmnr/ARC0000025875_0666465023.0001 ' , Options => dbms_logmnr . addfile ) ;
八、开始挖日志
九、将logmnr的数据暂时保存在一个表里面,免得再次查询时候不用再次添加归档日志
insert /*+ append */ into hjm_logmnr select * from v $ logmnr_contents ;
做这一步之前注意将 nls_date_format 改成 ' yyyy-mm-dd hh24:mi:ss ' ,不然泰文乱码,时间会变成问号。
九、导出脚本,用脚本做回滚,注意SQL_UNDO中的delete语句末尾有rowid,不能直接用,需要用正则表达式替换掉。
select regexp_replace ( replace ( SQL_UNDO , ' "HR_TTM" ' , ' "HR_TTM2" ' ) , ' and ROWID.+; ' , ' ; ' )
from hjm_logmnr
WHERE
SEG_NAME = ' TA_ABSDOCS ' AND
SEG_OWNER = ' HR_TTM '
order by to_char ( TIMESTAMP , ' yyyy-mm-dd hh24:mi:ss ' ) desc ;
spool off
spool TA_ABSDOC_undosql . txt
select regexp_replace ( replace ( SQL_UNDO , ' "HR_TTM" ' , ' "HR_TTM2" ' ) , ' and ROWID.+; ' , ' ; ' )
from hjm_logmnr
WHERE
SEG_NAME = ' TA_ABSDOC ' AND
SEG_OWNER = ' HR_TTM '
order by to_char ( TIMESTAMP , ' yyyy-mm-dd hh24:mi:ss ' ) desc ;
spool off
去掉脚本的头部的语句和末尾返回多少多少行的文字,在hr_ttm2下执行这2个脚本,实现数据回滚。
另外,我们来看一下:
from hjm_logmnr
WHERE
SEG_NAME = ' TA_ABSDOC ' AND
SEG_OWNER = ' HR_TTM ' 2 3 4 5
6 /
TO_CHAR ( MAX ( TIMESTA TO_CHAR ( MIN ( TIMESTA
----------------- -- -------------------
2011 - 06 - 09 21 : 20 : 26 2011 - 06 - 09 15 : 31 : 54
SQL >
SQL >
SQL >
SQL >
SQL > l
1 select to_char ( max ( TIMESTAMP ) , ' yyyy-mm-dd hh24:mi:ss ' ) , to_char ( min ( TIMESTAMP ) , ' yyyy-mm-dd hh24:mi:ss ' )
2 from hjm_logmnr
3 WHERE
4 SEG_NAME = ' TA_ABSDOC ' AND
5 * SEG_OWNER = ' HR_TTM '
SQL > l4
4 * SEG_NAME = ' TA_ABSDOC ' AND
SQL > c / TA_ABSDOC / TA_ABSDOCS
4 * SEG_NAME = ' TA_ABSDOCS ' AND
SQL >
TO_CHAR ( MAX ( TIMESTA TO_CHAR ( MIN ( TIMESTA
----------------- -- -------------------
2011 - 06 - 09 21 : 20 : 26 2011 - 06 - 09 15 : 37 : 39
归档日志是从14:53开始,而这2个表的变动,是在15:30之后才有的(min(TIMESTAMP是在15:30之后)。
也就是说从14:53分到15:30之前,这2个表一直是没动过的。因此,可以跟客户说,2个表的数据恢复到15:00的。
抬头一看,东方既白。唉,又熬了个通宵。