Notice there are a number of classification levels, allowing you to pick the most appropriate for the given occasion. When combined with Oracle's percentage of the operating system CPU consumption, level 2 provides insights into the CPU subsystem utilization, without running a single operating system command! You'll learn more about this in Chapter 5. When talking with management, I usually work at level 3, and if the managers can grasp more detail, I'll go to level 4. When talking with DBAs and devising solutions, I'll be working at level 5.

The ability to summarize complexity to enable a broader understanding is very desirable. The more senior the DBA, the more he tends to realize this challenge and value this skill. Acquiring technical prowess is required, but if you want to continue moving forward in your career, you must be able to transform very complex topics into seemingly very simple concepts. This is where ORTA and, more specifically, time classification shine.

For example, one way to explain the performance situation is to say, "Oracle's wait time is composed of 55% db file scattered reads, 35% db file sequential reads, and 10% various wait events." A more effective way to start the conversation would be to say, "Oracle response time is all about IO. And if you look into the details, you'll find that reading multiple blocks per request from the IO subsystem is what's really hurting performance." This more simplistic approach is not misleading and should not be condescending, yet it communicates exactly what needs to be understood.