After the workload is replayed on a test system, there may be some divergence in what is replayed compared to what was captured. There are numerous factors that can cause replay divergence, which can be analyzed using the workload replay report. The information contained in the workload replay report consists of performance and replay divergence.
Performance divergence may result when new algorithms are introduced in the replay system that affect the overall performance of the database. For example, if the workload is replayed on a newer version of Oracle Database, a new algorithm may cause specific requests to run faster, and the divergence will appear as a faster execution. In this case, this is a desirable divergence.
Data divergence occurs when the results of DML or SQL queries do not match results that were originally captured in the workload. For example, a SQL statement may return fewer rows during replay than those returned during capture.
Error divergence occurs when a replayed database call:
Encounters a new error that was not captured
Does not encounter an error that was captured
Encounters a different error from what was captured
The information contained in the workload replay report is divided into the following categories:
Details about the workload replay and the workload capture, such as job name, status, database information, duration and time of each process, and the directory object and path
Replay options selected for the workload replay and the number of replay clients that were started
Overall statistics about the workload replay and the workload capture (such as the total DB time captured and replayed, and the number of logins and transactions captured and replayed) and the corresponding percentages with respect to total system activity
Profile of the replayed workload
Replay divergence
Error divergence
DML and SQL query data divergence