Solution: RECOVER LOSS OF ONLINE REDO LOG


First check that ORACLE_HOME and ORACLE_SID are set correctly, and if not, do
so and re-start. Else, continue as follows.

Recover the loss of an inactive, online redo log group.

ALTER DATABASE CLEAR LOGFILE 'filename';

If there is more than one LOGFILE in the redo log group then you must
specify all the log files.

For example, the following fails:

SVRMGR> alter database clear logfile '/vobs/oracle/dbs/log3.log';
alter database clear logfile '/vobs/oracle/dbs/log3.log'
*
ORA-1514: error in log specification: no such log
ORA-1517: log member: '/vobs/oracle/dbs/log3.log

But, specifying all the log files in the group works:
SVRMGR> ALTER DATABASE CLEAR LOGFILE ('/vobs/oracle/dbs/t4.log','/vobs/oracle/;
Statement processed.

For more information Ref: Bug:763186


Solution Explanation:
=====================

The database, at open, does a check of log file headers and
found an online log that appears to be an incorrected restored file.
In this case it was not incorrect, but inactive. By issuing
the clear logfile, you can avoid going through an uneccessary
open resetlogs when applicable