Losing All Members of an Online Redo Log Group

Recovering After Losing All Members of an Online Redo Log Group

ocp 053

709. A database has three online redo log groups wi th one member each. A redo log member with the

status ACTIVE is damages while the database is running.

What is the first step you should take to solve this problem?

A.Attempt to Issue a checkpoint.

B.Restart the database usi ng the RESETLOGS option.

C.Drop the redo log number and create it in a different location.

D.Perform and incomplete recovery up to the most recent available redo log.

Answer: C 

答案解析：

参考：http://docs.oracle.com/cd/E11882_01/backup.112/e10642/osadvsce.htm#BRADV90049

根据官方文档，此题应该选A

Recovering After Losing All Members of an Online Redo Log Group

If a media failure damages all members of an online redo log group, then different scenarios can occur depending on the type of online redo log group affected by the failure and the archiving mode of the database.

If the damaged online redo log group is current and active, then it is needed for crash recovery; otherwise, it is not. Table 30-4 outlines the various recovery scenarios.

Table 30-4 Recovering After the Loss of an Online Redo Log Group

If the Group Is...	Then...	And You Should...
Inactive	It is not needed for crash recovery	Clear the archived or unarchived group.
Active	It is needed for crash recovery	Attempt to issue a checkpoint and clear the log; if impossible, then you must either use Flashback Database or restore a backup and perform incomplete recovery up to the most recent available redo log.
Current	It is the redo log that the database is currently writing to	Attempt to clear the log; if impossible, then you must either use Flashback Database or restore a backup and perform incomplete recovery up to the most recent available redo log.