Hot oracle RMAN backups
I have a question in regards to Oracle RMAN hot backups. The parent job of the Oracle backups in Netbackup is a zero byte file but is assigned a backup ID in Netbackup. It is also my understanding that this a control file and is needed to restore the DB's that were backed up. Can someone elaborate and confirm?
Also, the DBA's asked to extend the retention of these backups for a period of time. I did extend the retention on the backup id and it does show in the "Clinet Backups" report, but not in the "Images on Media" or the "Images on Disk" report. Why? I understand that this is a 0 byte file, but where is it stored especially if you need this file in order to restore the DB's.