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The accounting trace is probably the single most important trace for judging the performance of DB2 application programs. Using the accounting trace records, DB2 writes data pertaining to the following:

• CPU and elapsed time of the program
• EDM pool use
• Locks and latches requested for the program
• Number of get page requests, by bufferpool, issued by the program
• Number of synchronous writes
• Type of SQL issued by the program
• Number of COMMITs and ABORTs issued by the program
• Program’s use of sequential prefetch and other DB2 performance features

Estimated overhead: DB2 accounting class 1 adds approximately 3 percent CPU overhead. DB2 accounting classes 1, 2, and 3 together add approximately 5 percent CPU overhead. You cannot run class 2 or 3 without also running class 1.

Accounting trace classes 7 and 8 provide performance trace information at the package level. Enabling this level of tracing can cause significant overhead.