You execute the following Recovery Manager (RMAN) commands in the following order:
BACKUP VALIDATE DATABASE;
RECOVER CORRUPTION LIST;
Which (two tasks are performed by these commands? (Choose two.)
A.
Repair the corrupted blocks. If any. In the backup created.
B.
Populate V$COPY_CORRUPTION with names of files that have corrupted blocks.
C.
Back up the database after checking whether array of the files have corrupted blocks.
D.
Discover any corrupt blocks that are viewable with the
V$DATABASE_BLOCK_CORRUPTION view.
E.
Repair all corrupted blocks that have been logged in the
V$DATABASE_BLOCK_CORRUPTION
Explanation:
V$DATABASE_BLOCK_CORRUPTION displays information about database blocks that
were corrupted after the last backup.
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BACKUP…VALIDATE
Scans the specified files and verifies their contents, testing whether this file can be backed
up and whether the data blocks are corrupt. RMAN creates no output files.
This option is equivalent to using the VALIDATE command on the database files specified in
the backup. If you do not specify CHECK LOGICAL, then BACKUP..VALIDATE checks for
physical corruption only. If you specify CHECK LOGICAL, then BACKUP VALIDATE checks
for both physical and logical corruption.
RMAN populates the V$DATABASE_BLOCK_CORRUPTION view with any corruptions that
it finds.
You can use the SET MAXCORRUPT command to set a limit for the number of corrupt
blocks tolerated during the backup validation. The default is zero.
If you execute BACKUP INCREMENTAL with VALIDATE, then the behavior depends on
whether block change tracking is enabled. If change tracking is enabled, then RMAN
validates only changed blocks; otherwise, RMAN validates all blocks in the files included in
the backup.
Note: You cannot validate backups of backup sets.
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The following prerequisites apply to RECOVER BLOCK: (link)
The target database must run in ARCHIVELOG mode and be open or mounted with a
current control file.
RMAN can only recover blocks marked media corrupt. The
V$DATABASE_BLOCK_CORRUPTION view indicates which blocks in a file were marked
corrupt since the most recent BACKUP or BACKUP … VALIDATE command was run against
the file.
The backups of the data files containing the corrupt blocks must be full backups and not
proxy backups. If only proxy backups exist, then you can restore them to a nondefault
location on disk, in which case RMAN considers them data file copies. You can then use the
data file copies for block media recovery.
RMAN can use only archived redo log files for recovery. Block media recovery cannot
survive a missing or inaccessible log, although it can sometimes survive missing or
inaccessible records (see Oracle Database Backup and Recovery User’s Guide).
For RMAN to be able to search the flashback logs for good copies of corrupt blocks,
Flashback Database must be enabled on the target database.
For RMAN to be able to search a standby database for good copies of corrupt blocks, the
target database must be associated with a physical standby database in a Data Guard
environment. In addition, the physical standby database must be open read-only in managed
recovery.