Diagnosing the Database and Managing Performance - OCP: Oracle Database 12c Administrator Certified Professional - page 447

Analyze the Workload Replay Results
The basic steps to analyze the results are to view the capture report, view the replay report,
and compare the results. You can view the reports from the Database Replay page in EM
after the replay is complete:
1. Select the report of your choice from the View Workload Replay screen, as shown in
Figure 9.68.
FiGURe 9.68 Database Replay: View Workload Replay summary
2. We will not go into a detailed analysis of the report, but there are a few key sections of
the report to review:
■ Workload Captured
■ Workload Not Captured
■ SQL Tex t
■ Workload Filters
3. Key items to look for in the replay report are top SQL statements, performance diver-
gence, data divergence, and error divergence.
Performance divergence is usually due to infrastructure or configuration differences
between the capture and replay environments. In Figure 9.67 we can see that for the limited
amount of the captured workload that was replayed, the replay time was greater than the
capture time. Given this information, we need to further investigate to determine the bottle-
necks in the test system. Data divergence occurs when the DML and SQL statement results
in the replay system and capture system do not match. Error divergence occurs when the
errors do not match.