Incremental cumulative backup ?

Question

Oracle 11.2.0.2 / Windows 2008
Up till now, I've been running nightly 'full' backups but I've now decided to run Incremental Cumulative backups. What I plan to do is create a level '0' backup on a Monday night, and then run daily level '1' (cumulative) backups from Tuesday - Sunday and then for the whole process to start again for the following week. I've setup this up within enterprise manager (and I'm going to run them via enterprise manager) and it has produced the below scripts
Level 0
$rman_script="backup incremental level 0 cumulative device type disk tag '%TAG' database;
backup device type disk tag '%TAG' archivelog all not backed up delete all input;
allocate channel for maintenance type disk;
delete noprompt obsolete device type disk;
release channel;
&br_save_agent_env();
&br_prebackup($l_db_connect_string, $l_is_cold_backup, $l_use_rcvcat, $l_db_10_or_higher, $l_backup_strategy, "TRUE");
my $result = &br_backup();
exit($result);
Level 1
$rman_script="backup incremental level 1 cumulative device type disk tag '%TAG' database;
backup device type disk tag '%TAG' archivelog all not backed up delete all input;
allocate channel for maintenance type disk;
delete noprompt obsolete device type disk;
release channel;
&br_save_agent_env();
&br_prebackup($l_db_connect_string, $l_is_cold_backup, $l_use_rcvcat, $l_db_10_or_higher, $l_backup_strategy, "TRUE");
my $result = &br_backup();
exit($result);
At the moment, my retention policy is set to 31 days and the 'Retain at least the specified number of full backups for each datafile is set to '1'. Do I have to change this to cater for the above ?
Thanks in advance for any assistance

Answer 1

>'Retain at least the specified number of full backups for each datafile is set to '1'.
Are you referring to configuration in your MML -- NetBackup or Networker or the like ?
RMAN's retention policy is in terms of either redundancy (number of copies) or days (number of days).  You've defined it to be 31 days so the oldest backup that would not be obsoleted would be the L0 backup closest to sysdate-31 at any time.
Hemant K Chitale