人工手动冷备不完全恢复介绍(purge表不完全恢复)

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人工手动冷备不完全恢复介绍(purge表不完全恢复)

技术小美 2017-11-12 16:19:00 浏览548
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不完全恢复


不完全恢复的基本类型:
1)基于时间点 (until time): 使整个数据库恢复到过去的一个时间点前
2)基于scn (until change): 使整个数据库恢复到过去的某个SCN前
3)基于cancel (until cancel): 使整个数据库恢复到归档日志或当前日志的断点前


不完全恢复(Incomplete recover) 适用环境:
1)在过去的某个时间点重要的数据被破坏。
2)在做完全恢复时,丢失了归档日志或当前online redo log
3)当误删除了表空间时(有控制文件备份)
4)丢失了所有的控制文件,使用备份的控制文件恢复时  (条件满足时可以完全恢复)


传统的不完全恢复的操作步骤:
1)先通过logmnr 找到误操作的时间点
2)对现在的database做新全备
3)还原该时间点前所有的datafile
4)在mount状态下,对database做recover,恢复到误操作的时间点
5)将恢复出来的table做逻辑备份(exp)
6)再将全备还原
7)将导出的表导入database(imp)  


实验 1:恢复过去某个时间点误操作的table    (基于时间点的不完全恢复)   前提:有冷备份,日志,归档齐全


1)准备实验数据


SQL> select * from andy;


        ID
----------
         4


SQL> insert into andy values(5);


1 row created.


SQL> commit;


Commit complete.


SQL> drop table andy purge;


Table dropped.


2)查看日志,归档环境


SQL> set linesize 400
SQL> select * from v$log;


    GROUP#    THREAD#  SEQUENCE#      BYTES  BLOCKSIZE    MEMBERS ARC STATUS           FIRST_CHANGE#
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- -------------
         1          1         61   52428800        512          1 NO  CURRENT                1991534
         2          1         59   52428800        512          1 YES INACTIVE               1959769
         3          1         60   52428800        512          1 YES INACTIVE               1966481


SQL> alter system switch logfile;


System altered.


SQL> select name from v$archived_log;
NAME
----------------------------------------------------------------------------------------------------------




/home/oracle/archivelog/ORCL/archivelog/2014_12_01/o1_mf_1_47_b7rwlclg_.arc
/home/oracle/app/flash_recovery_area/ORCL/archivelog/2014_12_01/o1_mf_1_48_b7ryjgng_.arc
/home/oracle/app/flash_recovery_area/ORCL/archivelog/2014_12_01/o1_mf_1_49_b7rykz3l_.arc
/home/oracle/app/flash_recovery_area/ORCL/archivelog/2014_12_01/o1_mf_1_50_b7ryn3fl_.arc
/home/oracle/archivelog/1_51_860522448.dbf
/home/oracle/archivelog/1_52_860522448.dbf
/home/oracle/archivelog/1_53_860522448.dbf
/home/oracle/archivelog/1_54_860522448.dbf
/home/oracle/archivelog/1_55_860522448.dbf


NAME
----------------------------------------------------------------------------------------------------------
/home/oracle/archivelog/1_56_860522448.dbf
/home/oracle/archivelog/1_57_860522448.dbf
/home/oracle/archivelog/1_58_860522448.dbf
/home/oracle/archivelog/1_59_860522448.dbf
/home/oracle/archivelog/1_60_860522448.dbf
/home/oracle/archivelog/1_61_860522448.dbf


28 rows selected.


3)logmnr日志挖掘,找出purge时间点。


--日志挖掘至少要提前开SUPPLEME,如果没开,信息会报错
SQL> select supplemental_log_data_min,supplemental_log_data_pk,supplemental_log_data_ui from v$database;


SUPPLEME SUP SUP
-------- --- ---
YES      NO  NO
SQL> col member for a50;
SQL>  select * from v$logfile;


    GROUP# STATUS  TYPE    MEMBER                                             IS_
---------- ------- ------- -------------------------------------------------- ---
         3         ONLINE  /home/oracle/app/oradata/orcl/redo03.log           NO
         2         ONLINE  /home/oracle/app/oradata/orcl/redo02.log           NO
         1         ONLINE  /home/oracle/app/oradata/orcl/redo01.log           NO


SQL> select group#,status from v$log;


    GROUP# STATUS
---------- ----------------
         1 ACTIVE
         2 CURRENT
         3 INACTIVE


SQL>  select name from v$archived_log where name is not null order by 1;


NAME
-----------------------------------------------------------------------------------------
/home/oracle/app/flash_recovery_area/ORCL/archivelog/2014_12_01/o1_mf_1_48_b7ryjgng_.arc
/home/oracle/app/flash_recovery_area/ORCL/archivelog/2014_12_01/o1_mf_1_49_b7rykz3l_.arc
/home/oracle/app/flash_recovery_area/ORCL/archivelog/2014_12_01/o1_mf_1_50_b7ryn3fl_.arc
/home/oracle/archivelog/1_51_860522448.dbf
/home/oracle/archivelog/1_52_860522448.dbf
/home/oracle/archivelog/1_53_860522448.dbf
/home/oracle/archivelog/1_54_860522448.dbf
/home/oracle/archivelog/1_55_860522448.dbf
/home/oracle/archivelog/1_56_860522448.dbf
/home/oracle/archivelog/1_57_860522448.dbf
/home/oracle/archivelog/1_58_860522448.dbf


NAME
-----------------------------------------------------------------------------------------
/home/oracle/archivelog/1_59_860522448.dbf
/home/oracle/archivelog/1_60_860522448.dbf
/home/oracle/archivelog/1_61_860522448.dbf
/home/oracle/archivelog/ORCL/archivelog/2014_12_01/o1_mf_1_47_b7rwlclg_.arc


15 rows selected.


-- 利用redolog日志进行挖掘


SQL>  EXECUTE DBMS_LOGMNR.ADD_LOGFILE(LogFileName=>'/home/oracle/app/oradata/orcl/redo01.log',Options=>dbms_logmnr.new);


PL/SQL procedure successfully completed.


SQL>EXECUTE DBMS_LOGMNR.ADD_LOGFIL (LogFileName=>'/home/oracle/app/oradata/orcl/redo02.log',Options=>dbms_logmnr.ADDFILE);


PL/SQL procedure successfully completed.


SQL>EXECUTE DBMS_LOGMNR.ADD_LOGFILE(LogFileName=>'/home/oracle/app/oradata/orcl/redo03.log',Options=>dbms_logmnr.ADDFILE);


PL/SQL procedure successfully completed.


SQL>  execute DBMS_LOGMNR.START_LOGMNR(options=>dbms_logmnr.dict_from_online_catalog);


PL/SQL procedure successfully completed.


SQL>  col username for a10;
SQL> col sql_redo for a45;
SQL>  select username,scn,timestamp,sql_redo from v$logmnr_contents where seg_name='ANDY' order by scn;


USERNAME          SCN TIMESTAMP           SQL_REDO
---------- ---------- ------------------- ---------------------------------------------
ANDY          2000934 2014-12-11 09:47:15 drop table andy purge;        //找到purge时间


--利用归档进行日志挖掘


SQL> show parameter utl


NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
create_stored_outlines               string
utl_file_dir                         string


SQL> alter system set utl_file_dir='/home/oracle/logmnr' scope=spfile;


System altered.


SQL> startup force;


SQL> show parameter utl;


NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
create_stored_outlines               string
utl_file_dir                         string      /home/oracle/logmnr


SQL> execute dbms_logmnr_d.build('dict.ora','/home/oracle/logmnr',dbms_logmnr_d.store_in_flat_file);


PL/SQL procedure successfully completed.


SQL> execute dbms_logmnr.add_logfile(logfilename=>'/home/oracle/archivelog/1_61_860522448.dbf',options=>dbms_logmnr.new);


PL/SQL procedure successfully completed.


SQL> execute dbms_logmnr.start_logmnr(dictfilename=>'/home/oracle/logmnr/dict.ora',options=>dbms_logmnr.ddl_dict_tracking);


PL/SQL procedure successfully completed.


SQL> select username,scn,to_char(timestamp,'yyyy-mm-dd hh24:mi:ss'),sql_redo from v$logmnr_contents WHERE lower(sql_redo) like 'drop table%';


USERNAME                              SCN TO_CHAR(TIMESTAMP,' SQL_REDO
------------------------------ ---------- ------------------- --------------------------------------------------
ANDY                              2000934 2014-12-11 09:47:15 drop table andy purge;


SQL>  execute dbms_logmnr.end_logmnr;


PL/SQL procedure successfully completed.




4)关闭数据库,删除所有dbf,准备做不完全恢复


SQL> shutdown immdiate;
[oracle@11g logmnr]$ cd /home/oracle/app/oradata/orcl/
[oracle@11g orcl]$ rm -rf *.dbf


5)还原所有备份的数据文件


[oracle@11g orcl]$ cp /home/oracle/coldbak/*.dbf  /home/oracle/app/oradata/orcl/


6)根据log miner提供的信息,做基于时间点的不完全恢复


SQL> recover database until time '2014-12-11 09:47:15';
ORA-00279: change 1968596 generated at 12/10/2014 06:26:35 needed for thread 1
ORA-00289: suggestion : /home/oracle/archivelog/1_60_860522448.dbf
ORA-00280: change 1968596 for thread 1 is in sequence #60




Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
auto
ORA-00279: change 1991534 generated at 12/10/2014 07:25:45 needed for thread 1
ORA-00289: suggestion : /home/oracle/archivelog/1_61_860522448.dbf
ORA-00280: change 1991534 for thread 1 is in sequence #61




Log applied.
Media recovery complete.


说明:如果恢复过程中用到归档日志则输入 auto 。用到当前日志,则输入 filename 。 


7)resetlogs方式打开数据库


SQL> alter database open resetlogs;


Database altered.


8)验证
SQL> select * from andy;


        ID
----------
         5
         4


OK,转载请标明出处。



本文转自 张冲andy 博客园博客,原文链接:http://www.cnblogs.com/andy6/p/6274603.html   ,如需转载请自行联系原作者






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