一个OCA题目的疑惑(FAST_START_MTTR_TARGET)

原题:
121. What is the implication of setting the initialization parameter FAST_START_MTTR_TARGET to 0 in your
database?
A) MTTR Advisor would be disabled.
B) Redo Log Advisor would be disabled.
C) Automatic tuning of checkpoint would be disabled.
D) Checkpoint information would not be written to the alert log file.


参考答案:C

但是大家都在考虑A是否正确,首先说说C的正确性:
Automatic Checkpoint Tuning in 10g [ID 265831.1]
How to enable:
==============
Automatic checkpoint tuning is enabled by default. If it is disabled, by setting the parameter to zero explicitly, you can enable it by unsetting FAST_START_MTTR_TARGET or set it to a nonzero value. If you set this parameter to zero this feature will be disabled.
Note: this is different from defaulting (i.e. not setting) fast_start_mttr_target to 0.

可以证明C是正确的(有待验证,主要不明白怎么查询Automatic checkpoint tuning )

关于A的正确性,可以看看一下alert log,大家就会明白
Thu Feb 11 10:35:06 2010
ALTER SYSTEM SET fast_start_mttr_target=600 SCOPE=BOTH;
Thu Feb 11 10:35:20 2010
MTTR advisory was turned off because FAST_START_MTTR_TARGET was disabled.
Thu Feb 11 10:35:20 2010
ALTER SYSTEM SET fast_start_mttr_target=0 SCOPE=BOTH;


每当我设置fast_start_mttr_target=0的时候MTTR advisory 会自动关闭,所以我觉得A也是对的

你可能感兴趣的:(sql,C++,c,C#)