55 Which statement about recovering from the loss of a redo log group is true? A. If the lost redo l

55

Which statement about recovering from the loss of a redo 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.

Correct Answer: D

Section: (none)

Explanation

Explanation/Reference:

Explanation:

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.