Oracle Oracle Certifications 1Z0-053 Questions & Answers

• Question 41:

  If a log file becomes corrupted, it may cause the database to stale.

  How would you correct such a situation?

  A. Recover the online redo log from backup.

  B. Delete and re-create the log file.

  C. Use the ALTER DATABASE CLEAR LOGFILE command to clear the log file.

  D. Shut down the database and restart it.

  E. Shut down the database and then mount it. Clear the log file with the ALTER DATABASE CLEAR LOGFILE command and then restart the database with ALTER DATABASE OPEN RESETLOGS.

  Correct Answer: C

  If you don't use the ALTER DATABASE CLEAR LOGFILE command to clear log online, after the database restarted, the log file will be INVALID.

  So the simple way is to clear the log file directly.

• Question 42:

  Your database has a backup that was taken yesterday (Tuesday) between 13:00 and 15:00 hours. This is the only backup you have. You have lost all the archived redo logs generated since the previous Monday, but you have archived redo logs available from the previous Sunday and earlier. You now need to restore your backup due to database loss.

  A. 13:00 on Tuesday.

  B. 15:00 on Tuesday.

  C. Up until the last available archived redo log on Sunday.

  D. To any point; all the redo should still be available in the online redo logs.

  E. The database is not recoverable.

  Correct Answer: E

• Question 43:

  Which RMAN backup command is used to create the block-change tracking file?

  A. alter database create block change tracking file

  B. alter database enable block change file

  C. alter database enable block change tracking using file '/ora01/opt/block_change_tracking.fil'

  D. alter system enable block change tracking using file '/ora01/opt/block_ change_tracking.fil'

  E. alter system block change tracking on

  Correct Answer: C

• Question 44:

  What is the purpose of the recover command? (Choose all that apply.)

  A. Recover database datafiles from physical disk backup sets.

  B. Recover required incremental backups from physical disk backup sets.

  C. Recover required archived redo logs from physical disk backup sets.

  D. Apply incremental backups to recover the database.

  E. Apply archived redo logs to recover the database.

  Correct Answer: BCDE

• Question 45:

  What is the purpose of the list expired backup command?

  A. Lists all backups impacted by a resetlogs command

  B. Lists all backups that are subject to retention criteria

  C. Lists all backups that are missing associated physical backup set pieces

  D. Lists the status of datafile backup failures due to the use of the duration command

  E. Lists backups that cannot be used by the restore command because they have been marked as disabled

  Correct Answer: C

• Question 46:

  View the Exhibit to examine a portion of the output from the VALIDATE DATABASE command.

  Which statement is true about the block corruption detected by the command?

  

  A. No action is taken except the output in the Exhibit.

  B. The ADVISE FAILURE command is automatically called to display the repair script.

  C. The failure is logged into the Automatic Diagnostic Repository (ADR).

  D. The corruption is repaired by the command implicitly.

  Correct Answer: C

  Detection of Block Corruption (link)

  Oracle Database supports different techniques for detecting, repairing, and monitoring block corruption.

  The technique depends on whether the corruption is interblock corruption or intrablock corruption. In intrablock corruption, the corruption occurs within the block itself. This corruption can be either physical or logical. In aninterblock corruption, the corruption occurs between blocks and can only be logical.

  For example, the V$DATABASE_BLOCK_CORRUPTION view records intrablock corruptions, while the Automatic Diagnostic Repository (ADR) tracks all types of corruptions. Table 16-1 summarizes how the database treats different types of block corruption.

• Question 47:

  You have the following requirements in relation to the detection of block corruption for your database instance:

  Check for logical self-consistency of data blocks when modified in memory.

  Checksums are calculated before and after the block change.

  Checks are performed for the lost writes to the physical standby database.

  Which method would help you perform the above checks automatically?

  A. Set the DB_SECUREFILE parameter to PERMITTED.

  B. Set the DB_ULTRA_SAFE parameter to DATA_ONLY.

  C. Set the DB_LOCK_CHECKSUM parameter to TYPICAL.

  D. Set the DB_LOST_WRITE_PROTECT parameter to TYPICAL.

  Correct Answer: B

  

  Values:

  OFF

  When any of DB_BLOCK_CHECKING, DB_BLOCK_CHECKSUM, or

  DB_LOST_WRITE_PROTECT are explicitly set, no changes are made.

  DATA_ONLY

  DB_BLOCK_CHECKING will be set to MEDIUM.

  DB_LOST_WRITE_PROTECT will be set to TYPICAL.

  DB_BLOCK_CHECKSUM will be set to FULL.

  DATA_AND_INDEX

  DB_BLOCK_CHECKING will be set to FULL.

  DB_LOST_WRITE_PROTECT will be set to TYPICAL.

  DB_BLOCK_CHECKSUM will be set to FULL.

  

  Values:

  OFF or FALSE No block checking is performed for blocks in user tablespaces. However, semantic block checking for SYSTEM tablespace blocks is always turned on. LOW Basic block header checks are performed after block contents change in memory (for example, after UPDATE or INSERT statements, on-disk reads, or inter-instance block transfers in Oracle RAC). MEDIUM All LOW checks and full semantic checks are performed for all objects except indexes (whose contents can be reconstructed by a drop+rebuild on encountering a corruption). FULL or TRUE

  All LOW and MEDIUM checks and full semantic checks are performed for all objects.

• Question 48:

  You have not configured Oracle Managed Files (OMF) in your database. You do not want to scan the entire datafile every time an incremental backup is performed. You decide to enable the block change tracking feature. Which statement should you use to enable the block change tracking feature?

  A. ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;

  B. ALTER SYSTEM ENABLE BLOCK CHANGE TRACKING USING FILE ;

  C. ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE ;

  D. ALTER SYSTEM ENABLE BLOCK CHANGE TRACKING;

  Correct Answer: C

• Question 49:

  You enable block change tracking. You issue the following command:

  BACKUP INCREMENTAL LEVEL 0 DATABASE;

  The next day, you issue the following command:

  BACKUP INCREMENTAL LEVEL 1 CUMULATIVE DATABASE;

  Which statement about the use of the change tracking file is true?

  A. RMAN reads the block change tracking file only when it performs the incremental level 0 backup.

  B. RMAN reads the block change tracking file when it performs both incremental backups.

  C. RMAN reads the block change tracking file only when it performs the incremental level 1 backup.

  D. RMAN does not read the block change tracking file when it performs either incremental backup.

  Correct Answer: C

• Question 50:

  Which command do you use to generate a report of database incarnations?

  A. list incarnation of database

  B. report incarnation of database

  C. list database incarnation

  D. database incarnation list

  E. report database incarnation

  Correct Answer: A

  LIST INCARNATION OF DATABASE prod3;