Determining Backup File size, Prior to running the backup?

I kick off an RMAN script that runs either a full or an incremental backup. This is kicked off by a Java program. Just prior I need to verify that there is enough disk space to do the backup. I know how much free disk space is in the backup directory provided by the user. Is there a way to tell what the size of the resulting file is going to be, so I can notifiy the user if there is not enough disk space?

Currently it fills up the disk to 100%, doesn't provide an error in the output file, aborts the backup, and frees up the space it was using for the backup.

Using 9.2.0.1 Enterprise

Todd. Received on Wed Jan 21 2004 - 12:57:18 CST