Now let's combine our recommendations with response-time mathematics to anticipate change. The second analysis cycle will show the actual effect of our changes!

To summarize this exercise's performance situation, the online users are experiencing poor performance due to Oracle being required to retrieve blocks from the IO subsystem and then process them. There is plenty of CPU, IO, and memory capacity. It just needs to be shifted to maximize performance. The planned shifts are to increase Oracle's buffer cache to virtually eliminate all physical IO requests and to tune the most CPU-consuming SQL statement. Both changes will have a dramatic performance improvement impact.

It is always best and more reliable to focus on one change at a time. As anyone working in IT has experienced, multiple simultaneous changes can have unanticipated effects. We need to know the impact of each change. Therefore, only one change will be implemented at a time.