ACCT001, ACCT002, RPTS001, and RPTS002 represent the best opportunities for saving CPU, so examine those first. Without this type of summarized reporting, it’s difficult to do any sort of truly productive tuning. Most DBAs and systems programmers who lack these reports and look only at online monitors or plan table information are really just shooting in the dark.
Reporting to Management
To do this type of tuning, you need buy in from management and application developers. This can sometimes be the most difficult part because, unfortunately, most application tuning involves costly changes to programs. One way to demonstrate the potential ROI for programming time is to report the cost of application performance problems in terms of dollars. This is easy and amazingly effective!
The summarized reports can be used to display information on an application level. An in-house naming standard can be used to combine all the performance information from various packages into application-level summaries. This lets you classify applications and address the ones that use the most resources.
For example, if the in-house accounting application has a program naming standard where all program names begin with “ACCT,” then the corresponding DB2 package accounting information can be grouped by this header. Thus, the DB2 accounting report data for programs ACCT001, ACCT002, and ACCT003 can be grouped together, and their accounting information summarized to represent the “ACCT” application.
Most capacity planners have formulas for converting CPU time into dollars. If you get this formula from the capacity planner, and categorize the package information by application, you can easily turn your daily package summary report into an annual CPU cost per application. Figure 3 shows a simple chart developed using an in-house naming standard and a CPU-to-dollars formula. Give this report to the big guy and watch his head spin! This is a really great tool for getting those resources allocated to get the job done.
Make sure you produce a “cost reduction” report, in dollars, once a phase of the tuning has completed. This makes it perfectly clear to management what the tuning efforts have accomplished and gives incentive for further tuning efforts. Consider providing a visual representation of your data. A bar chart with before and after results can be highly effective in conveying performance tuning impact.
Finding the Statements of Interest