OCP-1Z0-053-V12.02-82题
82.Identify the three predefined server-generated alerts. (Choose three.)
A. Drop User
B. Tablespace Space Usage
C. Resumable Session Suspended
D. Recovery Area Low On Free Space
E. SYSTEM Tablespace Size Increment
Answer: BCD
答案解析：
参考：http://blog.csdn.net/rlhua/article/details/12683525
官方参考：http://docs.oracle.com/cd/E11882_01/server.112/e25494/monitoring.htm#ADMIN11247
Monitoring Database Operations with Server-Generated Alerts
A server-generated alert is a notification from the Oracle Database server of an impending problem. The notification may contain suggestions for correcting the problem. Notifications are also provided when the problem condition has been cleared.
Alerts are automatically generated when a problem occurs or when data does not match expected values for metrics, such as the following:
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Physical Reads Per Second
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User Commits Per Second
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SQL Service Response Time
Server-generated alerts can be based on threshold levels or can issue simply because an event has occurred. Threshold-based alerts can be triggered at both threshold warning and critical levels. The value of these levels can be customer-defined or internal values, and some alerts have default threshold levels which you can change if appropriate. For example, by default a server-generated alert is generated for tablespace space usage when the percentage of space usage exceeds either the 85% warning or 97% critical threshold level. Examples of alerts not based on threshold levels are:
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Snapshot Too Old -
Resumable Session Suspended -
Recovery Area Space Usage
An alert message is sent to the predefined persistent queue ALERT_QUE owned by the user SYS. Oracle Enterprise Manager reads this queue and provides notifications about outstanding server alerts, and sometimes suggests actions for correcting the problem. The alerts are displayed on the Enterprise Manager Database Home page and can be configured to send email or pager notifications to selected administrators. If an alert cannot be written to the alert queue, a message about the alert is written to the Oracle Database alert log.
Background processes periodically flush the data to the Automatic Workload Repository to capture a history of metric values. The alert history table andALERT_QUE are purged automatically by the system at regular intervals.