053-2

You plan to have a larger moving window size for the default system-defined moving window baseline
because you want to use the adaptive threshold.
Which statement factors in this consideration while increasing the size of the moving window.?
A. The collection level for the AWR should be set to BASIC.
B. The moving window size must be less than Undo Retention.
C. The moving window size should be greater than the Automatic Workload Repository (AWR) retention period.
D. The moving window size should be equal to or less than the Automatic Workload Repository (AWR) retention period.

移动窗口基线(Moving Window Baseline)
Oracle设计移动窗口基线是为了得到基于基线的度量。只有一个移动窗口基线，即Oracle内置的system moving baseline, 它使用AWR保留期内存在的所有AWR数据。可以自动产生并调整，即自适应阈值(Adaptive Thresholds)，system moving baseline的默认窗口大小必须小于等于当前AWR保留的时间，默认为8天。如果你要使用自适应阈值，可以考虑使用更大的移动窗口，例如30天，可以更精确地计算出阈值。若你需要增大移动窗口的大小，首先需要增加AWR的保留时间。