oracle丢失inactive日志文件的恢复操作过程

丢失非活动日志组的故障恢复
如果数据库丢失的是非活动(inactive)日志组,由于非活动日志组已经完成检查点,
数据库不会发生数据损失,此时只需要通过clear重建该日志组即可恢复.

先删除一个非活动日志组,模拟一次故障损失:

SQL> !rm /u01/app/oracle/product/10.2.0/oradata/jingyong/redo03.log

SQL> alter system switch logfile;

System altered.

SQL> alter system switch logfile;

System altered.

此时启动数据库,数据库会提示日志丢失

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.

Total System Global Area  167772160 bytes
Fixed Size                  1218316 bytes
Variable Size              67111156 bytes
Database Buffers           96468992 bytes
Redo Buffers                2973696 bytes
Database mounted.
ORA-00313: open failed for members of log group 3 of thread 1
ORA-00312: online log 3 thread 1:
'/u01/app/oracle/product/10.2.0/oradata/jingyong/redo03.log'

此时在mount状态,可以查看各日志组及日志文件的状态:

SQL> select * from v$log;
GROUP#     THREAD#    SEQUENCE#   BYTES     MEMBERS    ARC STATUS            FIRST_CHANGE# FIRST_TIME
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------
1          1          26         52428800            1 NO  INACTIVE         913689        06-JAN-13

3          1          28         52428800            1 NO  CURRENT          913701        06-JAN-13

2          1          27         52428800            1 NO  INACTIVE         913696        06-JAN-13
SQL> select * from v$logfile;

GROUP#     STATUS  TYPE    MEMBER                                                      IS_RECOVERY_DEST_FILE
---------- ------- ------- ----------------------------------------------------------- ---------------------
3                  ONLINE  /u01/app/oracle/product/10.2.0/oradata/jingyong/redo03.log  NO

2                  ONLINE  /u01/app/oracle/product/10.2.0/oradata/jingyong/redo02.log  NO

1                  ONLINE  /u01/app/oracle/product/10.2.0/oradata/jingyong/redo01.log  NO

清除该日志组后即可启动数据库:

SQL>alter database clear logfile group 3;
Database altered

SQL>alter database open;
Database altered

注意,如果数据库处于归档模式下,并且该日志组未完成归档则需要使用如下命令强制清除

alter database clear unarchived logfile group 3;

打开数据库之后,状态为stale的日志文件,在下次正常写入后,状态即可恢复正常:

SQL> select * from v$log;

GROUP#     THREAD#    SEQUENCE#   BYTES     MEMBERS    ARC STATUS            FIRST_CHANGE# FIRST_TIME
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------
1          1          2          52428800            1 NO  INACTIVE         914153        06-JAN-13

2          1          3          52428800            1 NO  INACTIVE         914157        06-JAN-13

3          1          4          52428800            1 NO  CURRENT          914164        06-JAN-13