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?
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.
Explanation:
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.
Resolving Performance Degradation Over Time