z/OS performance options for Db2

You can set z/OS® performance options for Db2 by using z/OS Workload Manager.

With Workload Manager (WLM), you define performance goals and assign a business importance to each goal. You define the goals for work in business terms, and the system decides how much resource, such as CPU and storage, should be given to the work to meet its goal.

WLM controls the dispatching priority based on the goals you supply. WLM raises or lowers the priority as needed to meet the specified goal. Thus, you do not need to fine-tune the exact priorities of every piece of work in the system and can focus instead on business objectives.

The three kinds of goals are:

Response time

How quickly you want the work to be processed.

Execution velocity

How fast the work should be run when ready, without being delayed for processor, storage, I/O access, and queue delay.

Discretionary

A category for low priority work for which you define no performance goals.

Response times are appropriate goals for user applications, such as QMF users running under the TSO address space goals, or users of CICS® using the CICS workload goals. You can also set response time goals for distributed users.

For Db2 address spaces, velocity goals are more appropriate. A small amount of the work done in Db2 is counted toward this velocity goal. Most of the work done in Db2 applies to user goals.