I hope you can see why Oracle wait-event analysis is far superior to traditional performance ratio analysis. As you read this book, you will learn how to exploit the wait interface, take it beyond just listening to Oracle, and also be made aware of how the wait interface can be shockingly misused, leading to an incorrect diagnosis.

I believe Oracle response-time analysis, or ORTA for short, is the most significant performance analysis method DBAs have at their disposal.12 ORTA allows DBAs to quantify (at least in part) a user's experience, to classify time, to anticipate both the application and operating system situation, and to quantify a solution's benefit. Thus, this approach transforms the traditionally defensive firefighting posture into a forward-thinking predictive posture. That is an impressive list!

Even wait-event analysis falls short compared to ORTA, because ORTA encapsulates wait-event analysis and takes it further. Shunning the advantages of ORTA and relying solely on a wait-event analysis will limit performance analysis in depth and scope, and opens up the possibility of a misdiagnosis. Those are condemning statements, but as you read this book, you will discover that they are true. Here, I will introduce the background and concepts of ORTA. In Chapters 5 and 9, I will detail how to perform the analysis, where to gather the necessary data, and other interesting details.