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

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 9692 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
9136 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_
---
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

GROUP# STATUS TYPE
---------- ------- -------
MEMBER
--------------------------------------------------------------------------------
IS_
---

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