You want to take the backup of the USERS tablespace. It has a single data file of 900 MB.
You have tape drives of 300 MB each. The SBT channel is configured for the RMAN. To
accomplish the backup, you issued the following RMAN command:
RMAN> BACKUP SECTION SIZE 300M TABLESPACE users;
Which two statements are true regarding the execution of the above command? (Choose
two.)
A.
The RMAN parallelizes the backup although the parallelism is not set for a channel.
B.
The backup piece size will be limited to 300 MB.
C.
The operation is accomplished using the default channel available.
D.
Three channels for the tape drive must be configured by setting the parallelism to three.
Explanation:
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.
Answers B and C is correct.
C is correct because I ran a test with only one channel
RMAN> SHOW ALL;
RMAN configuration parameters for database with db_unique_name AHEADPRD are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION ON;
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP OFF; # default
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO ‘%F’; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM ‘AES128’; # default
CONFIGURE COMPRESSION ALGORITHM ‘BASIC’ AS OF RELEASE ‘DEFAULT’ OPTIMIZE FOR LOAD TRUE ; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO ‘C:\APP\ALAN.OBRIEN\PRODUCT\11.2.0\DBHOME_1\DATABASE\SNCFAHEADPRD.ORA’; # default
RMAN> BACKUP SECTION SIZE 2M TABLESPACE users;
Starting backup at 02-MAR-16
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00004 name=D:\ORADATA\AHEADPRD\USERS01.DBF
backing up blocks 1 through 256
channel ORA_DISK_1: starting piece 1 at 02-MAR-16
channel ORA_DISK_1: finished piece 1 at 02-MAR-16
piece handle=D:\FLASH_RECOVERY_AREA\AHEADPRD\BACKUPSET\2016_03_02\O1_MF_NNNDF_TAG20160302T210243_CFGKQ384_.BKP tag=TAG20160302T210243 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00004 name=D:\ORADATA\AHEADPRD\USERS01.DBF
backing up blocks 257 through 512
channel ORA_DISK_1: starting piece 2 at 02-MAR-16
channel ORA_DISK_1: finished piece 2 at 02-MAR-16
piece handle=D:\FLASH_RECOVERY_AREA\AHEADPRD\BACKUPSET\2016_03_02\O1_MF_NNNDF_TAG20160302T210243_CFGKQ4HV_.BKP tag=TAG20160302T210243 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00004 name=D:\ORADATA\AHEADPRD\USERS01.DBF
backing up blocks 513 through 640
channel ORA_DISK_1: starting piece 3 at 02-MAR-16
channel ORA_DISK_1: finished piece 3 at 02-MAR-16
piece handle=D:\FLASH_RECOVERY_AREA\AHEADPRD\BACKUPSET\2016_03_02\O1_MF_NNNDF_TAG20160302T210243_CFGKQ5R8_.BKP tag=TAG20160302T210243 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 02-MAR-16
RMAN > LIST BACKUP;
…
BS Key Type LV Size Device Type Elapsed Time Completion Time
——- —- — ———- ———– ———— —————
19 Full 3.40M DISK 00:00:02 02-MAR-16
List of Datafiles in backup set 19
File LV Type Ckp SCN Ckp Time Name
—- — —- ———- ——— —-
4 Full 1924696 02-MAR-16 D:\ORADATA\AHEADPRD\USERS01.DBF
Backup Set Copy #1 of backup set 19
Device Type Elapsed Time Completion Time Compressed Tag
———– ———— ————— ———- —
DISK 00:00:02 02-MAR-16 NO TAG20160302T210243
List of Backup Pieces for backup set 19 Copy #1
BP Key Pc# Status Piece Name
——- — ———– ———-
19 1 AVAILABLE D:\FLASH_RECOVERY_AREA\AHEADPRD\BACKUPSET\2016_03_02\O1_MF_NNNDF_TAG20160302T210243_CFGKQ384_.BKP
20 2 AVAILABLE D:\FLASH_RECOVERY_AREA\AHEADPRD\BACKUPSET\2016_03_02\O1_MF_NNNDF_TAG20160302T210243_CFGKQ4HV_.BKP
21 3 AVAILABLE D:\FLASH_RECOVERY_AREA\AHEADPRD\BACKUPSET\2016_03_02\O1_MF_NNNDF_TAG20160302T210243_CFGKQ5R8_.BKP
You can use just a default channel instead of DOP (Degree of parallelism), in which case the file sections are generated serially.