Como recuperar a perda de um arquivo de log redo.(ORA-00313 ,ORA-00312).O erro que você começa receber e ORA-00313, ORA-00312. Então vamos ver como podemos corrigir isso.
[oracle@DCG023 RCAT]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Mon Sep 9 17:57:40 2013
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup mount;
ORACLE instance started.
Total System Global Area 1603411968 bytes
Fixed Size 2213776 bytes
Variable Size 1006635120 bytes
Database Buffers 587202560 bytes
Redo Buffers 7360512 bytes
Database mounted.
SQL> select GROUP#,STATUS from V$LOG;
GROUP# STATUS
---------- ----------------
3 INACTIVE
2 CURRENT
1 INACTIVE
SQL> ALTER DATABASE DROP LOGFILE GROUP 3;
Database altered.
ALTER DATABASE ADD LOGFILE GROUP 4 ('/u01/oracle/oradata/RCAT/redo04.log') SIZE 50M;
Database altered.
SQL> RECOVER DATABASE UNTIL CANCEL;
Media recovery complete.
SQL> ALTER DATABASE OPEN RESETLOGS;
Database altered.