Which three statements are true about Flashback Database?
A.
Flashback logs are written sequentially, and are archived.
B.
Flashback Database uses a restored control file to recover a database.
C.
The Oracle database automatically creates, deletes, and resides flashback logs in the Fast Recovery Area.
D.
Flashback Database can recover a database to the state that it was in before a reset logs operation.
E.
Flashback Database can recover a data file that was dropped during the span of time of the flashback.
F.
Flashback logs are used to restore to the blocks’ before images, and then the redo data may be used to roll
forward to the desired flashback time.
Explanation:
http://docs.oracle.com/database/121/BRADV/flashdb.htm#BRADV529 http://docs.oracle.com/database/121/
BRADV/glossary.htm#BRADV90169
Correct.
Detailed explanation:
Not B: If the database control file is restored from backup or re-created, all accumulated flashback log information is discarded. You cannot use FLASHBACK DATABASE to return to a point in time before the restore or re-creation of a control file.
C: flashback logs – Oracle-generated logs used to perform flashback database operations. The database can only write flashback logs to the fast recovery area. Flashback logs are written sequentially and are not archived. (Not A) They cannot be backed up to disk.
D: You can use Flashback Database to reverse most unwanted changes to a database if the data files are intact. You can return a database to its state in a previous incarnation, and undo the effects of an ALTER DATABASE OPEN RESETLOGS statement.
Not E: You cannot use Flashback Database alone to retrieve a dropped data file. If you flash back a database to a time when a dropped data file existed in the database, only the data file entry is added to the control file. You can only recover the dropped data file by using RMAN to fully restore and recover the data file.
F: When you use Flashback Database to rewind a database to a past target time, the command determines which blocks changed after the target time and restores them from the flashback logs. The database restores the version of each block that is immediately before the target time. The database then uses redo logs to reapply changes that were made after these blocks were written to the flashback logs.