Consider the following scenario for your database:
-Backup optimization is enabled in RMAN. The recovery window is set to 7 days in RMAN. The most recent backup to disk for the TOOLS tablespace was taken on November 3, 2007.
The TOOLS tablespace is read-only since November 4, 2007.
On November 23, 2007, you issue the RMAN command to back up the database to disk. Which statement is true regarding the backup of the TOOLS tablespace?
A. The RMAN backup fails because the TOOLS tablespace is read-only
B. The RMAN skips the backup of the tablespace because backup optimization is enabled
C. The RMAN makes backup because optimization can be enabled only for backups to disk
D. The RMAN makes the backup because no backup of the tablespace exists within the seven day window
此题和 42 题考点类似，是关于备份优化。由于只读表空间在 7 天时间窗口中没有备份，所以会进行备份
D 正确（备份优化会被备份策略覆盖），B 错误
A 错误，只读表空间也是可以备份的
C 错误。备份优化也可以再介质管理器上（磁带设备）使用。
启用了备份优化：RMAN> CONFIGURE BACKUP OPTIMIZATION ON;
可以使用下列命令语法配置恢复窗口保留策略：
RMAN> CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF <天数>DAYS;
本题设置为 7 天