Incrementally updated backups are an efficient way to implement an image copy backup strategy. This technique instructs RMAN to first create image copies of data files; then, the next time the backup runs, instead of creating a fresh set of image copies, RMAN makes an incremental backup (changes to blocks since the image copy was created) and applies that incremental backup to the image copies.
If you have the disk space available for full image copies of your database and you want the flexibility to use the image copies directly, in the event of a media failure, consider this backup strategy.
One potential disadvantage of this approach is that if you’re required to restore and recover to some point in the past, you can only restore and recover to the point at which the image copies were last updated with the incremental backup.
