There are many options these days for measuring and monitoring Oracle(r) Database application performance. This book is about the one that endures as the best foundation there is for understanding Oracle performance: the Oracle extended SQL trace feature. This book is the course book for the 1-day Mastering Oracle Trace Data course taught by the author, Cary Millsap. It is t a book about discarding your Oracle fixed views or your monitoring tools that poll them. It is a book about how to look at Oracle performance ather way, a way that has worked extraordinarily well for many of us. It's about new ways of thinking about performance using new tools for understanding aspects of your applications that you've never understood before. Contents include: Part one - A coherent framework for understanding all aspects of performance beginning with foundational definitions, case studies illustrating the use of Oracle extended SQL trace data in the performance problem and repair context, detailed descriptions of how to create and obtain extended SQL trace data in different languages and application contexts, detailed explanations of how to understand the story that the trace data is trying to tell you, detailed reference material about Oracle timing measurements and how to use them. Part two - Over 100 pages of worked examples (case studies) illustrating how to analyze and solve performance problems with Oracle-based applications, using the Method R Profiler, Method R Tools, and Method R Trace commercial software packages. Part three - A perspective on why trace files are still important in this modern age of ASH and AWR, and a list of explanations by dozens of Oracle professionals about why they use trace data today.