If only one member of an inactive online redo log group has been lost, you can use the recovery procedure described in the previous section. Experienced users can correct this error without shutting down the database. For more information, see the Oracle documentation.
The recovery procedure is different when the following situation occurs:
The database pauses because a redo log switch to an online redo log file was unsuccessful. None of the members in this inactive online redo log group can be read or written to.
If the problem is temporary (for example, incorrect access rights), you only need to correct it, and you can then use the group again. If the files have been destroyed, however, the group can not be used again.
No data is lost, providing the missing redo log file was fully archived and the archived copy can be read.
Recovery Procedure
Proceed as follows during recovery:
shutdown abort
ABORT is needed because the database system cannot carry out a proper shutdown, due to the damaged group.
connect internal
startup mount
alter database noarchivelog;
alter database drop group <group number>;
or as individual files with
alter database drop logfile '<file name>' [,'<file name>'];
alter database add logfile '<complete file name>';
alter database archivelog;