Configuring and Backing Up Oracle Databases Using RMAN - OCP: Oracle Database 12c Administrator Certified Professional - page 151

exeRCiSe 3.2 (continued)
channel ORA_DISK_1: starting piece 1 at 11-SEP-13
channel ORA_DISK_1: finished piece 1 at 11-SEP-13
piece handle=C:\ORACLE\FAST_RECOVERY_AREA\ORCL
\BACKUP SET\2013_09_11\O1_MF_ANNNN_TAG20080911T190742_4DMJ7H29_.BKP
tag=TAG20080911T190742 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
channel ORA_DISK_1: deleting archived log(s)
archived log file name=C:\ORACLE\ARCH\ORCL
\ARC00093_0662757171.001 RECID=92 STAMP=665176062
Finished backup at 11-SEP-13
Starting Control File and SPFILE Autobackup at 11-SEP-13
piece handle=C:\ORACLE\FAST_RECOVERY_AREA\ORCL
\AUTOBACKUP\2013_09_11\O1_MF_S_665176080_4DMJ7SOT_.BKP comment=NONE
Finished Control File and SPFILE Autobackup at 11-SEP-13
RMAN Incremental Backups
Incremental database backups are a way to quickly back up your database. In the follow-
ing sections, we will discuss incremental backups. First, you'll learn about configuring for
incremental backups. Next, we will look at the two different kinds of incremental backups
that are available, and then you'll learn how to actually do incremental backups.
Configuring for Incremental Backups
Technically, you don't have to configure anything to do an incremental backup. RMAN will
perform an incremental backup when you issue the appropriate backup command. However,
without any configuration, RMAN must inspect each block and determine whether it has
indeed changed since the last backup and if it must go into the backup image.
Optionally you can create a block-change tracking file that will keep track of blocks
that have changed since the last full or incremental backup. This can significantly reduce
the time it takes to perform an incremental backup of your database because it removes the
need for Oracle to inspect each data block to determine if it's been changed since the last
backup. Figure 3.4 demonstrates the block-change tracking file.
The block-change tracking file can track only a maximum of seven different
incremental level-1 backups. After the seventh backup, the initial level-0
backup records will be overwritten in the block-change tracking file. This
will result in RMAN having to scan all database blocks on subsequent
incremental backups. Thus, you should limit incremental backups without
an intervening level 0 to a maximum of seven.