OCP-1Z0-053-200题-143题-49

QUESTION 143

Which statement about recovering from the loss of aredo log group is true?

A. If the lost redo log group is ACTIVE, you should first attempt to clear the log file.

B. If the lost redo log group is CURRENT, you must clear the log file.

C. If the lost redo log group is ACTIVE, you must restore, perform cancel-based incomplete recovery, and

open the database using the RESETLOGS option.

D. If the lost redo log group is CURRENT, you must restore, perform cancel-based incomplete recovery, and

open the database using the RESETLOGS option.

Answer: D

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Explanation/Reference:

Section: Backup, Recovery & Recovery Manager (RMAN)

If the lost redo log group is CURRENT, you must restore, perform cancel-based incomplete recovery, and open

the database using the RESETLOGS option. A redo log group with a CURRENT status indicates that LGWR is

currently writing to it. To recover from this failure, you must restore the database from a whole backup and

perform cancel-based incomplete recovery. Then, you should open the database using the RESETLOGS

option.

The option that states if the lost redo log group is ACTIVE, you should first attempt to clear the log file is

incorrect. If the lost redo log group has a status of ACTIVE, it is needed for instance recovery. In that situation,

you should first attempt to perform a checkpoint. After the checkpoint, the log file is no longer required for

instance recovery.

The option that states if the lost redo log group is CURRENT, you must clear the log file is incorrect.You would

clear the log file only if the status of the lost redo log group was INACTIVE. After clearing the log file, the log

file may be reused.

The option that states if the lost redo log group is ACTIVE, you must restore, perform cancel-based incomplete

recovery, and open the database using the RESETLOGS option. These actions are only necessary if the log

file has a CURRENT status, which indicates LGWR is currently writing to it.