Database Software

Hello, I am currently using RMAN and OEM to manage my backups. The database backups are over 20GB now and I would like to compress them. Here is my current RMAN scriptthat I schedule in OEM. I am using 9.2.

CROSSCHECK BACKUP;
CROSSCHECK COPY;
CROSSCHECK backup of database;
CROSSCHECK backup of controlfile;
CROSSCHECK archivelog all;


run {
allocate channel Channel1 type disk format '/backup/oracle/oem_sets/b_%u_%p_%c';
backup
( database include current controlfile );

backup ( archivelog all not backed up 2 times );

}
allocate channel for maintenance device type disk;
delete archivelog until time 'sysdate - 7' backed up 2 times to disk;
delete obsolete device type disk;


How can I modify this script to use compression if it is supported in 9i?

Thank you,

David