• Redo current损坏


       如果损坏的是current redo log (select group#,sequence#,archived,status from v$log;)

       有两种情况:

    A、   数据库是正常关闭的。当前日志组的损坏就可以直接用alter database clear unarchived logfile group n来重建。

    启动数据库到mount状态

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

        GROUP#  SEQUENCE# ARC STATUS

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

             1          0 YES UNUSED

             3          3 NO  CURRENT

                 2          2 YES INACTIVE

    SQL> alter database clear unarchived logfile group 3; 

    Database altered.

    SQL> alter database open;

     

    Database altered.

    B、   如果数据库是非正常关闭(shutdown abort),current redo log 损坏,最好的恢复办法就是通过不完全恢复,可以保证数据库的一致性,但会丢失数据。

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

        GROUP#  SEQUENCE# ARC STATUS

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

             1         32 NO  CURRENT

             3         31 YES INACTIVE

             2         30 YES INACTIVE

     

    执行clear logfile group 1会报如下错误。

    SQL> alter database clear unarchived logfile group 1;

    ERROR at line 1:

    ORA-01624: log 1 needed for crash recovery of instance orcl (thread 1)

    ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/orcl/redo01.log'

          此时需要进行不完全恢复

          RMAN> restore database;

    Starting restore at 02-DEC-12

    using channel ORA_DISK_1

    channel ORA_DISK_1: starting datafile backup set restore

    channel ORA_DISK_1: specifying datafile(s) to restore from backup set

    channel ORA_DISK_1: restoring datafile 00001 to /u01/app/oracle/oradata/orcl/system01.dbf

    channel ORA_DISK_1: restoring datafile 00002 to /u01/app/oracle/oradata/orcl/sysaux01.dbf

    channel ORA_DISK_1: restoring datafile 00003 to /u01/app/oracle/oradata/orcl/undotbs01.dbf

    channel ORA_DISK_1: restoring datafile 00004 to /u01/app/oracle/oradata/orcl/users01.dbf

    channel ORA_DISK_1: reading from backup piece /u01/app/oracle/backup/full_ORCL_20121202_12_1.bak

    channel ORA_DISK_1: piece handle=/u01/app/oracle/backup/full_ORCL_20121202_12_1.bak tag=TAG20121202T141019

    channel ORA_DISK_1: restored backup piece 1

    channel ORA_DISK_1: restore complete, elapsed time: 00:00:45

    Finished restore at 02-DEC-12

          SQL> recover database until cancel;

    ORA-00279: change 274326 generated at 12/02/2012 14:10:20 needed for thread 1

    ORA-00289: suggestion : /u01/app/oracle/oradata/arch/1_22_800911110.dbf

    ORA-00280: change 274326 for thread 1 is in sequence #22

    Specify log: {<RET>=suggested | filename | AUTO | CANCEL}

    Auto

    …………

    ORA-00279: change 274396 generated at 12/02/2012 14:11:18 needed for thread 1

    ORA-00289: suggestion : /u01/app/oracle/oradata/arch/1_32_800911110.dbf

    ORA-00280: change 274396 for thread 1 is in sequence #32

    ORA-00278: log file '/u01/app/oracle/oradata/arch/1_31_800911110.dbf' no longer

    needed for this recovery

    ORA-00308: cannot open archived log

    '/u01/app/oracle/oradata/arch/1_32_800911110.dbf'

    ORA-27037: unable to obtain file status

    Linux-x86_64 Error: 2: No such file or directory

    Additional information: 3

    SQL> alter database open resetlogs;

    Database altered.

    恢复到当前日志的SEQUENCE#为32,不完全恢复结束。这种办法恢复的数据库会丢失当前联机日志中的事务数据。恢复成功之后,记得再做一次数据库的全备份。

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  • 原文地址:https://www.cnblogs.com/liang545621/p/9405858.html
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