QUESTION 141
You are tuning RMAN to optimize performance. You want tape I/O to be asynchronous when you perform tape
backups.
Which action should you take?
A. Set the BACKUP_TAPE_IO_SLAVES parameter to FALSE.
B. Set the BACKUP_TAPE_IO_SLAVES parameter to TRUE.
C. Use compression when performing tape backups.
D. Configure multiple SBT channels.
Answer: B
同204题：http://blog.csdn.net/rlhua/article/details/14452523
Explanation/Reference:
Section: Backup, Recovery & Recovery Manager (RMAN)
You should set the BACKUP_TAPE_IO_SLAVES parameter to TRUE. When this parameter is set to TRUE,
RMAN uses I/O server processes to perform reads and writes when performing backups, copies, or restoresto
or from tape. When asynchronous tape I/O is configured, tape buffers are allocated from the SGA, rather than
the PGA. With asynchronous I/O, the server process can perform multiple I/O operations at the same time.For
example, it can begin a read/write operation and perform other tasks while waiting for the current I/Ooperation
to finish. You should note that the support for asynchronous I/O is dependent on the operating system. Not all
operating systems support asynchronous tape I/O.
You should not set the BACKUP_TAPE_IO_SLAVES parameter to FALSE. This would configure RMAN to use
synchronous tape I/O, which is the default value. W ith synchronous tape I/O, a server process can perform
only one operation at a time, and tape buffers are allocated from the PGA.
All of the other options are incorrect. Using compression or multiple channels does not configure RMAN to use
asynchronous tape I/O.