You notice a performance change in your production Oracle database and you want to know which change has made this performance difference. You generate the Compare Period Automatic Database Diagnostic Monitor (ADDM) report to further investigation. Which three findings would you get from the report? 

Answer options:

A. It detects any configuration change that caused a performance difference in both time periods.
B. It identifies any workload change that caused a performance difference in both time periods.
C. It detects the top wait events causing performance degradation.
D. It shows the resource usage for CPU, memory, and I/O in both time periods.
E. It shows the difference in the size of memory pools in both time periods.
F. It gives information about statistics collection in both time periods.

ABD

Keyword: shows the difference. * Full ADDM analysis across two AWR snapshot periods Detects causes, measure effects, then correlates them Causes: workload changes, configuration changes Effects: regressed SQL, reach resource limits (CPU, I/O, memory, interconnect) Makes actionable recommendations along with quantified impact * Identify what changed / Configuration changes, workload changes * Performance degradation of the database occurs when your database was performing optimally in the past, such as 6 months ago, but has gradually degraded to a point where it becomes noticeable to the users. The Automatic Workload Repository (AWR) Compare Periods report enables you to compare database performance between two periods of time. While an AWR report shows AWR data between two snapshots (or two points in time), the AWR Compare Periods report shows the difference (ABE) between two periods (or two AWR reports with a total of four snapshots). Using the AWR Compare Periods report helps you to identify detailed performance attributes and configuration settings that differ between two time periods.