But our journey has just begun. Just like a doctor, we must also understand Oracle's physiology to come up with solutions. Now we will continue into the heart of Oracle, where mysterious algorithms and data structures reside. The framework developed in this and the previous chapter will be filled in with Oracle internal workings and how the various pieces fit together. Only with this knowledge can the guessing stop and spot-on solutions be developed.

1 My original "Direct Connection Identification Using Oracle's Wait Interface" paper has had thousands and thousands of downloads. It quickly became the foundation upon which all of my performance analyses were based. This paper is still available from the OraPub web site (go to http://www.orapub.com and search for "direct contention").

3 As I'll detail in the Chapter 4, there are occasions where Oracle records that a session is consuming CPU when actually the session is waiting in the CPU run queue.