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 not 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 another 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: Chapter 1 ''Thinking Clearly about Performance'' - over twenty brief sections that prescribe a coherent framework for understanding all aspects of performance beginning with foundational definitions. Chapter 2 ''Making Friends with the Oracle Database'' - a sequence of case studies illustrating the use of Oracle extended SQL trace data in the performance problem diagnosis and repair context. Chapter 3 ''Oracle Extended SQL Trace'' - a detailed explanation of where Oracle's trace data elements come from and how to assemble them into a trustworthy description of how applications consume time. Chapter 4 ''Oracle Database Timed Event Reference'' - an overview of what the Oracle timed events mean, how to learn more than your documentation can tell you, and how to respond to problems caused by excessive call counts or excessive call latencies. Chapter 5 ''Cases in Oracle Trace Data Analysis'' - seven case studies illustrating how to use the Method R Tools commercial software package (not included with the book) to analyze and solve problems with Oracle-based application performance.