OCP-1Z0-053-V12.02-302题

302.You issue the following command:

RMAN>CONFIGURE BACKUP OPTIMIZATION ON;

What is the result of this command on your backups?

A. An incremental backup strategy will be used automatically.

B. Read-only datafiles will not be backed up as long as backups of those files already exist and those backups meet established retention criteria.

C. RMAN will configure itself for maximum performance at the cost of CPU.

D. RMAN will configure itself for minimal OS/CPU impact at the cost of time to back up the database.

E. RMAN will automatically compress backups.

Answer: B

答案解析：

参考：备份优化： http://blog.youkuaiyun.com/rlhua/article/details/12312463

备份优化是指：通过跳过未更改的文件（如 已经备份的只读和脱机数据文件）优化整个数据库备份。

启用了备份优化：RMAN> CONFIGURE BACKUP OPTIMIZATION ON;