Figure 9-28. Shown is the operating system analysis information. Compared to Figure 9-22, Oracle CPU consumption dropped to 17%, and the operating system CPU utilization dropped from 28% to 20%. Since the utilization significantly dropped, we should not expect a large increase in the workload.

At this point, the only way to decrease CPU-related response time is to either use faster CPUs or reduce the SQL statement logical IO consumption (tune or balance). While additional CPUs may provide more CPU capacity, Oracle and the operating system are not able to fully take advantage of the existing four cores (for details, see the scalability discussion near the end of this chapter).

The application situation has indeed changed, as shown in Figure 9-29. First, we can see that no significant physical IO is being consumed! Thus means increasing the buffer cache had its intended affect. We were hoping for a 50% decrease in elapsed time, to around 0.316 ms/exec. What actually occurred was an elapsed time drop from 0.632 to 0.266, which is a 58% decrease in response time! So, we met and exceeded our objective. It appears the users are also able to get more work done because the SQL statement execution rate increased from 25.6 exec/sec (see Figure 9-24) to 27.1 exec/sec (Figure 9-30).