Oracle Oracle Certifications 1Z0-053 Questions & Answers

• Question 271:

  Because of a logical corruption in your production database, you wanted to perform Tablespace Point in Time Recovery (TSPITR). But before you start the recovery, you queried the TS_PITR_OBJECTS_TO_BE_DROPPED view and realized that there are a large number of objects that would be dropped when you start the recovery by using this method. You want to preserve these objects.

  Which option must you use to perform TSPITR and preserve the object?

  A. Perform Export before TSPITR and Import after TSPITR

  B. Move objects to another schema that has the same tablespace assigned

  C. Perform Incomplete Recovery before TSPITR with the Log Sequence Number (LSN)

  D. Perform Incomplete Recovery before TSPITR with the System Change Number (SCN)

  Correct Answer: A

• Question 272:

  Which of the following restrictions are NOT true with respect to tablespace point-in-time recovery? (Choose all that apply.)

  A. The target database must be in NOARCHIVELOG mode.

  B. No backup is required of the database before you perform a TSPITR.

  C. You must have all archived redo logs generated since the last backup up to the point to which you want to restore the transport set.

  D. If you rename a tablespace, you can not perform a TSPITR to any point in time before that rename operation occurred.

  E. If you have tables in tablespace_1 that have associated constraints in tablespace_2, then you must transport both tablespaces.

  Correct Answer: AB

• Question 273:

  You issued the following RMAN command to back up the database:

  RMAN> RUN{ ALLOCATE CHANNEL c1 DEVICE TYPE sbt BACKUP DATABASE TAG quarterly KEEP FOREVER RESTORE POINT FY06Q4; }

  Which two statements are true regarding the backup performed? (Choose two.)

  A. Archived redo log files are backed up along with data files.

  B. Only data files are backed up and a restore point named FY06Q4 is created.

  C. Archived log files are backed up along with data files, and the archived log files are deleted.

  D. The command creates a restore point named FY06Q4 to match the SCN at which this backup is consistent.

  Correct Answer: AD

  Section: Monitoring and Tuning RMAN

  Refer to here.

  keepOption

  Overrides any configured retention policy for this backup so that the backup is not considered obsolete, as shown in Example 2-26.

  You can use the KEEP syntax to generate archival database backups that satisfy business or legal requirements. The KEEP setting is an attribute of the backup set (not individual backup piece) or image copy.

  Note: You cannot use KEEP with BACKUP BACKUPSET.

  With the KEEP syntax, you can keep the backups so that they are considered obsolete after a specified time (KEEP UNTIL), or make them never obsolete (KEEP FOREVER). As shown in Example 2-27, you must be connected to a recovery

  catalog when you specify KEEP FOREVER.

  Note: You can use CHANGE to alter the status of a backup generated with KEEP. See Also: keepOption for more information about backups made with the KEEP option Creating a Consistent Database Backup for Archival Purposes This

  example uses a keepOption to create an archival backup set that cannot be considered obsolete for one year. The example backs up the database, archives the redo in the current online logs to ensure that this new backup is consistent, and

  backs up only those archived redo log files needed to restore the data file backup to a consistent state. The BACKUP command also creates a restore point to match the SCN at which this backup is consistent. The FORMAT parameter must

  be capable of creating multiple backup pieces in multiple backup sets.

  BACKUP DATABASE

  FORMAT '/disk1/archival_backups/db_%U.bck'

  TAG quarterly

  KEEP UNTIL TIME 'SYSDATE + 365'

  RESTORE POINT Q1FY06;

• Question 274:

  The BACKUP_TAPE_IO_SLAVES parameter is set to FALSE for the database instance.

  Which statement is true while performing a tape backup in an RMAN session?

  A. The tape I/O performed is asynchronous

  B. The tape buffer is allocated from the System Global Area (SGA)

  C. The tape buffer is allocated from the Program Global Area (PGA)

  D. Oracle I/O uses an interrupt mechanism to determine when each I/O completes

  Correct Answer: C

  Tape I/O Slaves RMAN allocates the tape buffers in the System Global Area (SGA) or the Program Global Area (PGA), depending on whether I/O slaves are used. If you set the initialization parameter BACKUP_TAPE_IO_SLAVES=true, then RMAN allocates tape buffers from the SGA. Tape devices can only be accessed by one process at a time, so RMAN starts as many slaves as necessary for the number of tape devices. If the LARGE_POOL_SIZE initialization parameter is also set, then RMAN allocates buffers from the large pool. If you set BACKUP_TAPE_IO_SLAVES=false, then RMAN allocates the buffers from the PGA. If you use I/O slaves, then set the LARGE_POOL_SIZE initialization parameter to dedicate SGA memory to holding these large memory allocations. This parameter prevents RMAN I/O buffers from competing with the library cache for SGA memory. If I/O slaves for tape I/O were requested but there is not enough space in the SGA for them, slaves are not used, and a message appears in the alert log.

  The parameter BACKUP_TAPE_IO_SLAVES specifies whether RMAN uses slave processes rather than the number of slave processes. Tape devices can only be accessed by one process at a time, and RMAN uses the number of slaves necessary for the number of tape devices.

• Question 275:

  You performed the RMAN database backup with the KEEP option.

  Which two statements are true regarding this backup? (Choose two.)

  A. The backup contains data files, the server parameter file, and the control file even if the control file autobackup is disabled.

  B. The KEEP option overrides the configured retention policy.

  C. The backup contains only data files and archived redo log files.

  D. The KEEP option is an attribute of an individual backup piece.

  Correct Answer: AB

• Question 276:

  You are managing an Oracle Database 11g database. You want to take a backup on tape drives of the USERS tablespace that has a single data file of 900 MB. You have tape drives of 300 MB each. To accomplish the backup, you issued the following RMAN command:

  RMAN>BACKUP SECTION SIZE 300M TABLESPACE users;

  What configuration should be effected to accomplish faster and optimized backups by using the above command?

  A. The SBT channel must be configured, with the default parallelism setting for the SBT device set to 1.

  B. The COMPATIBLE initialization parameter for the database instance must be set to at least 10.0.

  C. The SBT channel must be configured, with the parallelism setting for the SBT device set to 3.

  D. The SBT channel must be configured, with the MAXPIECESIZE set to 300 MB.

  Correct Answer: C

  Dividing the Backup of a Large Data File into Sections (link) If you specify the SECTION SIZE parameter on the BACKUP command, then RMAN creates a backup set in which each backup piece contains the blocks from one file section. A file section is a contiguous range of blocks in a file. This type of backup is called a multisection backup. Note: You cannot specify SECTION SIZE with MAXPIECESIZE. The purpose of multisection backups is to enable RMAN channels to back up a single large file in parallel. RMAN divides the work among multiple channels, with each channel backing up one file section in a file. Backing up a file in separate sections can improve the performance of backups of large datafiles.

  If a multisection backup completes successfully, then none of the backup sets generated during the backup contain a partial data file. If a multisection backup is unsuccessful, then it is possible for the RMAN metadata to contain a record for a partial backup set. RMAN does not consider partial backups for restore and recovery. You must use the DELETE command to delete the partial backup set.

  If you specify a section size that is larger than the size of the file, then RMAN does not use multisection backup for the file. If you specify a small section size that would produce more than 256 sections, then RMAN increases the section size to a value that results in exactly 256 sections.

  To make a multisection backup:

  1.

  Start RMAN and connect to a target database and recovery catalog (if used).

  2.

  If necessary, configure channel parallelism so that RMAN can make the backup parallel.

  3.

  Execute BACKUP with the SECTION SIZE parameter.

  For example, suppose that the users tablespace contains a single data file of 900 MB. Also assume that three SBT channels are configured, with the parallelism setting for the SBT device set to 3. You can break up the data file in this

  tablespace into file sections as shown in the following example:

  BACKUP

  SECTION SIZE 300M

  TABLESPACE users;

  In this example, each of the three SBT channels backs up a 300 MB file section of the users data file.

• Question 277:

  View the Exhibit and examine the output of the query in different times when the following command runs in an RMAN sessions:

  RMAN> BACKUP DATABASE FILESPERSET 2;

  The database has seven data files. Why is the %_COMPLETE refreshed to 13.59 in the third output after reaching 88.77?

  Exhibit:

  

  A. Because the progress is reported for each data file

  B. Because the progress is reported for each backup set

  C. Because other RMAN sessions have issued the same BACKUP command

  D. Because new data files have been added to the database while the RMAN backup is in progress

  Correct Answer: B

• Question 278:

  Multiple RMAN sessions are connected to the database instance. Examine the following output when backup commands are running in server sessions: What could have helped you to correlate server sessions with channels?

  

  A. Implement RMAN multiplexing

  B. Set the DEBUG ON in the RMAN script

  C. Specify the command ID in the RMAN script

  D. Use a tag with the RMAN BACKUP command

  Correct Answer: C

• Question 279:

  Which statement describes the significance of the CHANGE FAILURE command in RMAN? (Choose all that apply.)

  A. It is used to change failure priority only for HIGH or LOW priorities.

  B. It is used to execute the advised repair script.

  C. It is used to change failure priority only for the CRITICAL priority.

  D. It is used to explicitly close the open failures.

  E. It is used to inform the database about the repair after the repair script executes.

  Correct Answer: AD

• Question 280:

  You are managing an Oracle Database 11g database. You want to take the backup of MULT_DATA, a big file tablespace of size 100 TB on tape drive, but you have tapedrives of only 10 GB each.

  Which method would accomplish the task quickly and efficiently?

  A. parallel image copy backup

  B. backup with MAXPIECESIZE configured for the channel

  C. parallel backup with MAXPIECESIZE configured for the channel

  D. intrafile parallel backup

  Correct Answer: D

  The MAXPIECESIZE option is to limit the size of backup piece. not to split the big file into pieces.

  Configuring the Maximum Size of Backup Pieces Backup piece size is an issue when it exceeds the maximum file size permitted by the file system or media management software. You can use the MAXPIECESIZE parameter of the CONFIGURE CHANNEL or ALLOCATE CHANNEL command to limit the size of backup pieces.

  For example, to limit the backup piece size to 2 gigabytes or less, you can configure the automatic DISK channel as follows and then run BACKUP DATABASE:

  CONFIGURE CHANNEL DEVICE TYPE DISK MAXPIECESIZE 2G; BACKUP DATABASE;

  We should use the SECTION SIZE option to split the big file into sections to the multiple backup devices.

  SECTION SIZE sizeSpec Specifies the size of each backup section produced during a data file backup.

  By setting this parameter, RMAN can create a multisection backup. In a multisection backup, RMAN creates a backup piece that contains one file section, which is a contiguous range of blocks in a file. All sections of a multisection backup are the same size. You can create a multisection backup for a data file, but not a data file copy. File sections enable RMAN to create multiple steps for the backup of a single large data file. RMAN channels can process each step independently and in parallel, with each channel producing one section of a multisection backup set.

  If you specify a section size that is larger than the size of the file, then RMAN does not use multisection backup for the file. If you specify a small section size that would produce more than 256 sections, then RMAN increases the section size to a value that results in exactly 256 sections.

  Depending on where you specify this parameter in the RMAN syntax, you can specify different section sizes for different files in the same backup job. Note: You cannot use SECTION SIZE with MAXPIECESIZE or with INCREMENTAL LEVEL 1.