As you can see, this report pulls together a lot of information, consolidating and formatting it to give analysts a jump-start in their ORTAs.

The first section shown in Figure 2-15 provides a number of workload metrics common to the Load Profile section in both Statspack and AWR. This information is useful when comparing different response-time snapshots. Keep in mind that a decrease in the response time is to be expected if the workload decreases. To ensure you don't fall into the trap of thinking the system is performing better, you need to know the snapshot workloads.

The second section is the response time summary. This provides a high-level view of the response time components. In Figure 2-15, the total service time is 10 seconds of CPU, and the total wait time is 621 seconds. Written another way, during the 120-second interval, Oracle processes consumed only 10 seconds of CPU time and waited 621 seconds. The wait time is classified into IO time and non-IO time. In Figure 2-15, you can see the IO wait time is 615 seconds and the non-IO wait time is only 6 seconds. Clearly, Oracle processes are spending a significant portion of their time waiting for blocks outside the Oracle buffer cache!