RMAN Compressed Backups

RMAN Backups in Oracle Database 10g Standard Edition enables us to take compressed backups. "AS COMPRESSED BACKUPSET" is the addition in the default backup command:

BACKUP AS COMPRESSED BACKUPSET DATABASE PLUS ARCHIVELOG;

Well, that should be good, so I put the backup command at test for my newly migrated 10g Database. Here we go...

My Normal RMAN Backup takes an average of 30 minutes to complete, generating around 20.5 GB of Backupset for a 40GB Database.
So, I am expecting anything close to 40-50% compression (backupset size from 10-12 GB) after using the new command, and I am expecting the job to take more than 30 minutes to finish (say between 1-1:30 hrs).

And yet again, Oracle makes my day, today!!! I not only finish the job in less than 30 minutes, but guess what!, The compression is magnificent. The job finished at an average of 14 mins (superb) and the compression is almost 85-90%, i.e. backupset size was 2.5 GB (Mind Blowing). Talk about the Performance Gains and Storage Save.

RMAN> BACKUP AS COMPRESSED BACKUPSET DATABASE;
Starting backup at
06-MAR-10
using channel ORA_DISK_1
channel ORA_DISK_1: starting compressed full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
.
.
.
input datafile fno=00001 name=E:\ORACLE\ORADATA\ORCL\SYSTEM01.DBF
input datafile fno=00003 name=E:\ORACLE\ORADATA\ORCL\SYSAUX01.DBF
input datafile fno=00002 name=E:\ORACLE\ORADATA\ORCL\UNDOTBS01.DBF
input datafile fno=00004 name=E:\ORACLE\ORADATA\ORCL\USERS01.DBF
input datafile fno=00005 name=E:\ORACLE\ORADATA\ORCL\TOOLS01.DBF
channel ORA_DISK_1: starting piece 1 at 06-MAR-10
channel ORA_DISK_1: finished piece 1 at 06-MAR-10
piece handle=E:\ORACLE\BACKUP\RMAN\ORCL\ORCL_KTL7T94E_1_1_20100306
tag=TAG20100306T153854 comment=NONE
channel ORA_DISK_1: starting piece 2 at 06-MAR-10
channel ORA_DISK_1: finished piece 2 at 06-MAR-10
piece handle=E:\ORACLE\BACKUP\RMAN\ORCL\ORCL_KTL7T94E_2_1_20100306
tag=TAG20100306T153854 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:14:01
Finished backup at 06-MAR-10
Starting Control File and SPFILE Autobackup at 06-MAR-10
piece handle=\\BLADE5\MIS\BACKUP\RMAN\ORCL\C-1235707396-20100306-16 comment=NONE
Finished Control File and SPFILE Autobackup at 06-MAR-10

RMAN> BACKUP AS COMPRESSED BACKUPSET archivelog all;
Starting backup at 06-MAR-10
current log archived
using channel ORA_DISK_1
channel ORA_DISK_1: starting compressed archive log backupset
channel ORA_DISK_1: specifying archive log(s) in backup set
input archive log thread=1 sequence=1120 recid=1107 stamp=712943759
channel ORA_DISK_1: starting piece 1 at 06-MAR-10
channel ORA_DISK_1: finished piece 1 at 06-MAR-10
piece handle=E:\ORACLE\BACKUP\RMAN\ORCL\ORCL_KVL7TA4H_1_1_20100306
tag=TAG20100306T155601 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:08
Finished backup at 06-MAR-10
Starting Control File and SPFILE Autobackup at 06-MAR-10
piece handle=\\BLADE5\MIS\BACKUP\RMAN\ORCL\C-1235707396-20100306-17 comment=NONE
Finished Control File and SPFILE Autobackup at 06-MAR-10