New Features for Administrators - Question 020

Why can setting too low a value for the FAST_START_MTTR_TARGET parameter reduce your overall database performance?

A. Data blocks have to be written more frequently by DBWR.

B. Redo blocks have to be written more frequently by LGWR.

C. You need to substantially increase the size of your database buffer cache to hold the additional checkpoint records.

D. You need to substantially increase the size of your redo buffer cache to hold the additional checkpoint records.

Answer: A

Explanation:

If you set a value for the FAST_START_MTTR_TARGET too low DBWR will write the data blocks more frequently to reduce recovery time in accordance with the FAST_START_MTTR_TARGET parameter. It can cause the overall database performance degradation.

Incorrect Answers

B: It will not make LGWR to write redo blocks more frequently: data blocks will be written more frequently by DBWR.

C: You don’t need to substantially increase the size of your database buffer cache to hold the additional checkpoint records.

D: You don’t need to substantially increase the size of your redo buffer cache to hold the additional checkpoint records.

OCP Oracle9i Database: New Features for Administrators, Daniel Benjamin, p. 42-45

Chapter 2: Availability Enhancements

Oracle 9i New Features, Robert Freeman, p. 73-75

Chapter 3: New Oracle9i Availability and Recoverability Features