RMAN学习之四：丢失非当前的联机重做日志。

1、查看日志组和日志文件。

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

    GROUP#  SEQUENCE#    MEMBERS ARCHIV STATUS
---------- ---------- ---------- ------ --------------------------------
         1          0          1 YES    UNUSED
         2          0          1 YES    UNUSED
         3          1          1 NO     CURRENT

SQL> select group#, member from v$logfile;

    GROUP# MEMBER
-------------------------------------------------------------------------------------------------------------------------
         3 /u01/app/oracle/oradata/orcl/redo03.log
         2 /u01/app/oracle/oradata/orcl/redo02.log
         1 /u01/app/oracle/oradata/orcl/redo01.log

GROUP3联机日志组为当前状态，对应的联机日志文件时/u01/app/oracle/oradata/orcl/redo03.log，其他两组就是非当前联机日志组。

2、删掉一组非当前联机日志组文件。

SQL> host rm '/u01/app/oracle/oradata/orcl/redo01.log';

SQL> startup
ORA-32004: obsolete and/or deprecated parameter(s) specified
ORACLE instance started.

Total System Global Area  285212672 bytes
Fixed Size                  1218992 bytes
Variable Size              79693392 bytes
Database Buffers          201326592 bytes
Redo Buffers                2973696 bytes
Database mounted.
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/orcl/redo01.log'

SQL> select instance_name, status from v$instance;

INSTANCE_NAME                    STATUS
-------------------------------- ------------------------
orcl                             MOUNTED

3、修复日志文件。

SQL> alter database clear logfile GROUP 1;

Database altered.

SQL> alter database open;

Database altered.