An Oracle process time contribution increase does increase end-to-end response time, but understanding the details is becoming more and more complicated. Here are just of few of the time consumers between the database and the end user: cloud computing, security checks, application servers, web servers, web services, and load-balancing algorithms.

In the not-so-distant past, everything except the users and their terminals resided on the database server. Now, as shown in Figure 5-13, different architectural components are spread out (potentially) in different parts of world. The key to diagnosing a performance problem is understanding where the data flow is being blocked or taking a relatively long time to respond. When both the Oracle client and server processes resided on the database server, the problem nearly always resided on the database server. Now, with the various architectural components dispersed, the problem can be spread all over the world.

Figure 5-13. A simplified Oracle architecture consisting of key timing components: the end user, the user's web browser, Oracle's client process, and the Oracle server process residing on the database server. For a strong diagnosis, we need time consumed for each component and between each component.