A. RMAN will attempt to make the backup run as fast as possible without any IO limitations.
B. RMAN will automatically restrict the number of channels in use to one.
C. RMAN will spread the backup IO over the total duration stated in the backup command.
D. RMAN will skip any datafile that currently is involved in an IO operation.
RMAN will retry backing up the datafile later and an error will be raised at the end of the backup if the datafile cannot be backed up.
E. Datafiles will be backed up; those having the lowest current number of IO operations will be backed up first.
答案：（C）
解析：
BACKUP命令
MINIMIZE {LOAD | TIME},对于磁盘备份,可以使用MINIMIZE TIME以最大地速度进行备份
或MINIMIZE LOAD来降低备份的速度从而减少系统的负载.使用MINIMIZE LOAD将占用指定的整个duration
如果是MINIMIZE TIME,则最近备份的文件将给予最低的备份优先级,这种机制在连续的备份窗口中提供了数据库的
最终的complete备份,好象不同的数据文件以round-robbin形式被备份一样.