20. You have set Tablespace Full Metrics Threshold values for the USERS tablespace as follows:
Warning (%): 90
Critical (%): 95
Which background process is responsible for issuing alerts when the threshold is crossed?
A.System monitor (SMON)
B.Process monitor (PMON)
C.Memory manager process (MMAN)
D.Manageability Monitor process (MMON)
Answer: D
答案解析：
可管理性监视器进程(MMON)，可执行各种与可管理性相关的后台任务，例如：
• 每当给定的度量超过其阈值时发出预警
• 通过衍生附加进程（MMON 从属进程）获取快照
• 捕获近期已做修改的SQL 对象的统计值
The manageability monitor process (MMON)performs many tasks related to the Automatic Workload Repository (AWR). For example, MMON writes when a metricviolates its threshold value, taking snapshots, and capturing statistics value for recently modified SQL objects.
官方参考：http://docs.oracle.com/cd/E11882_01/server.112/e40540/process.htm#BABJAIBD