单项选择题 View the Exhibit to examine the output of the DBA_OUTSTANDING_ALERTS view. After 30 minutes， you executed the following command：  SQL> SELECT reason，metric_value FROM dba_outstanding_alerts； REASON         METRIC_VALUE  ------------------------------------------------------------  ------------  Tablespace [TEST] is [28 percent]full  28.125  What could be the reason for the elimination of the other rows in the output（）

单项选择题 The job to gather optimizer statistics for objects runs as part of the automatic maintenance window inyour database instance. At a certain point of time， the maintenance window closes before the statisticsare gathered for all objects.  Which statement is true in this scenario（）

多项选择题 Your database instance is functional for the past one month. The Automatic Workload Repository（AWR） snapshot retention is set to 7 and the STATISTICS_LEVEL initialization parameter is set to TYPICAL.  You receive a complaint about the poor performance of the database between 7 PM and 9 PM of theprevious day.  Choose two actions any of which can be referred to first to diagnose the problem. （）