Real application testing with database replay

Oracle Database Replay provides a new way to test changes to a database system by reproducing the real user workload in a test environment. It helps to identify potential problems after software or hardware upgrades, patches, or changes to database parameters, schema or data. Any interesting workload period of a production database system can be captured with minimal overhead. The captured workload can be used to drive a test system while maintaining the concurrency and load characteristics of the real production workload. The replay does not depend on any other software including the application itself. It reliably reproduces the captured workload to support early diagnosis and troubleshooting. In this paper we discuss the analysis of replay results and introduce a new compare-period report, which assists with a detailed performance comparison of the capture and its replays with respect to changes. We demonstrate its usefulness in a case study involving an upgrade for a Siebel financial application, where Database Replay identifies performance problems after the upgrade and helps correcting them.