Account Strings and Performance Groups
A Performance Group (PG) must be specified for every account string in use, except for DBC and SYSTEMUSERINFO. The account strings for these user IDs cannot be changed.
Priority Scheduler and Performance Groups
Priority Scheduler (PS) manages the allotment of system resources among concurrently running transactions based on their defined relative priority. This is accomplished through assigning each request to a default PG.
The definition of the PG within PS determines how that request obtains CPU resources over the course of the execution of the request.
Enabled TASM Workloads
When TASM workload definition (Category 3) is enabled, the Priority Scheduler PG portion of the account string is ignored for purposes of priority assignment. Instead, workload classification determines the priority of the request.
However, for the small amount of time that the first request of a session is being parsed prior to classification into a workload, the PG within the account string is used to establish priority.