I use the following script to backup archivelogs ...

Code:
replace script backup_al_all {
  execute script alloc_all_disks;
  backup
    filesperset 20
    format 'f:\frman\oracle\admin\rman\al_t%t_s%s_p%p'
    (archivelog all);
  execute script rel_all_disks;
}
Now, I want to delete the archive log backups dating one month back. How can I do this ?

For datafile backup, I do the following ...

Code:
list all backupset of database;

allocate channel for delete type disk;
change backupset (number_from_list) delete;
Now, how can I do a similar maintenance for archive log backupsets ?

Thanks for your input.