DB2 Version 9.7 for Linux, UNIX, and Windows
DB2 Version 9.7 for Linux, UNIX, and Windows
Arithmetic mean of the estimated costs for coordinator DML activities at nesting level 0 associated with this service subclass or work class since the last reset. If the internally tracked average has overflowed, the value -2 is returned. For service subclasses, this monitor element returns -1 when COLLECT AGGREGATE ACTIVITY DATA for the service subclass is set to NONE or BASE. For work classes, this monitor elements returns -1 if no COLLECT AGGREGATE ACTIVITY DATA EXTENDED work action is specified for the work class. For workloads, this monitor element returns -1 when COLLECT AGGREGATE ACTIVITY DATA for the workload is set to NONE or BASE. Units are timerons.
For service classes, the estimated cost of an activity is counted only towards the service subclass in which the activity enters the system. When you remap activities between service subclasses with a REMAP ACTIVITY action, the coord_act_est_cost_avg mean of the service subclass you remap an activity to is unaffected.
| Event Type | Logical Data Grouping | Monitor Switch |
|---|---|---|
| Statistics | event_scstats | - |
| Statistics | event_wcstats | - |
| Statistics | event_wlstats | - |
Use this statistic to determine the arithmetic mean of the estimated costs of coordinator DML activities at nesting level 0 that are associated this service subclass, workload, or work class that completed or aborted since the last statistics reset.
This average can also be used to determine whether or not the histogram template used for the activity estimated cost histogram is appropriate. Compute the average activity estimated cost from the activity estimated cost histogram. Compare the computed average with this monitor element. If the computed average deviates from the true average reported by this monitor element, consider altering the histogram template for the activity estimated cost histogram, using a set of bin values that are more appropriate for your data.