A. The current control file is not automatically backed up every time you perform a backup.
B. The backups save space on the storage media.
C. While performing backups across a network， the network bandwidth is reduced.
D. The backups consist of backup pieces.

A. when you change the name of a datafile
B. when you drop a table from the database
C. when you take an export of the database
D. when you back up the database using OS utilities
E. when you issue an ALTER SYSTEM SWITCH LOGFILE statement
F. when you issue a BACKUP command from inside the RMAN run block