Is it possible to merge a differential backup into a full backup using SQLBackup? The reason I ask is that we have to keep 7 days of backups on disk. Using differentials, this means 1 full and 6 differentials. After day 7, I would like to merge the full and the oldest so I can keep on making only differentials. Without a "merge" function, we'd have to make another full and keep the old one for another week.