Your database is running in archivelog mode and regular nightly backups are taken. Due to
a media failure, the current online redo log group, which has one member, is lost and the
instance is aborted.
Examine the steps to recover the online redo log group and move it to a new location.
1.Restore the corrupted redo log group.
2.Restore the database from the most recent database backup.
3.Perform an incomplete recovery.
4.Relocate the member of the damaged online redo log group to a new location.
5.Open the database with the resetlogs option.
6. Issue a checkpoint and clear the log.
Identify the required steps in the correct order.
A.
1, 3, 4, 5
B.
6, 3, 4, 5
C.
2, 3, 4, 5
D.
6, 4, 3, 5
C is correct
Losing an Active Online Redo Log Group
If the database is still running and the lost active redo log is not the current log, then issue the ALTER SYSTEM CHECKPOINT statement. If successful, then the active redo log becomes inactive, and you can follow the procedure in “Losing an Inactive Online Redo Log Group”. If unsuccessful, or if your database has halted, then perform one of procedures in this section, depending on the archiving mode.
The current log is the one LGWR is currently writing to. If a LGWR I/O fails, then LGWR terminates and the instance crashes. In this case, you must restore a backup, perform incomplete recovery, and open the database with the RESETLOGS option.
To recover from loss of an active online redo log group in ARCHIVELOG mode:
If the media failure is temporary, then correct the problem so that the database can reuse the group when required. If the media failure is not temporary, then use the following procedure.
Begin incomplete media recovery, recovering up through the log before the damaged log.
Ensure that the current name of the lost redo log can be used for a newly created file. If not, then rename the members of the damaged online redo log group to a new location. For example, enter:
ALTER DATABASE RENAME FILE “?/oradata/trgt/redo01.log” TO “/tmp/redo01.log”;
ALTER DATABASE RENAME FILE “?/oradata/trgt/redo01.log” TO “/tmp/redo02.log”;
Open the database using the RESETLOGS option:
ALTER DATABASE OPEN RESETLOGS;
Note:
All updates executed from the endpoint of the incomplete recovery to the present must be re-executed.
C
http://docs.oracle.com/cd/B19306_01/backup.102/b14191/recoscen.htm#i1006437
If the group is Current Then it is the log that the database is currently writing to And you should Attempt to clear the log; if impossible, then you must restore a backup and perform incomplete recovery up to the most recent available redo log.
C
C
http://otndnld.oracle.co.jp/document/products/oracle10g/102/doc_cd/backup.102/B19192-03/recoscen.htm#CACFFJFB
C