Figure 5-17. To enable Oracle database servers to handle an increasing number of end users, Oracle created server processes that could be shared among client processes. This was brilliant design, because in an OLTP environment, server processes remain very idle.

This resulted in what Oracle CEO Mr. Ellison coined network computing. While many have dismissed his prophetic words, modern-day web architectures have proved him right. In fact, vendors today are now selling low-processing computers known as netbooks. As Figure 5-18 shows, what essentially happened is the end user's computer is focused on display and navigation, while all other processing is handled by an increasingly dizzying array of computing systems.

Figure 5-18 is in some ways misleading because it implies a one-to-one relationship from the end user to the server process. In addition to accounting for a specific client's activity on a shared server, with application servers, web server, connection pooling of all kinds and at various layers, the task of associating an end user's activity to part of a server processing is nearly impossible. This created not only a performance analyst problem, but at a basic level, also a support issue. Suppose an end user calls her support department with an issue. How does the support department know what the end user is truly doing? Many times this is not possible, so the support technician must make inferences. To truly understand what the user is doing, the user's activity must be isolated in a controlled environment. But what if the problem is the result of noncontrolled environment issues? Now diagnosing user experience issues is no longer just muddy, it's nearly impossible to isolate with satisfactory clarity.