By integrating the Oracle Recovery Manager (RMAN) into the SAP backup program BRBACKUP – with the SAP backup library or an external backup library – you can make incremental backups, even if the structure of the database has been changed. An example of a structure change is when a data file is added. This is not possible using RMAN on its own.
Save sets are created each time a System Backup to Tape (SBT) backup library is used. Save sets are units that are created on the backup medium. Each save set contains one or more files. During incremental backups, the changes are normally backed up in a single save set. If new files were added to the database since the last full backup, a second save set is created containing the backups of the new files. For more information, see RMAN Save-Set Grouping. This means that you do not need to make a full backup of the entire database immediately after database extensions.
In subsequent incremental backups during the cycle, any changes that are made to files that existed when the last full backup was made are saved in one save set. Any new files are fully saved (that is, not just the changes) in the other save set. This method also has the advantage that you can be more specific about what you want to restore when restoring an incremental backup.