- Should show mostly SRB charges…
– Prefetch activity - TCB charges should be looked at…
– Extend and Format…. how many objects and how often
– CloseRule=Y…. Generates CPU/TCB overhead
When looking at the cpu charges to the Database Manager address space, one should expect most of the total charge to be for SRB mode.
Prefetch runs in SRB mode, and this generates these charges. TCB mode charges are usually caused by either extend and format activity, or having a closerule of Y on objects. Even when objects are not actually closed because DSMAX has not been exceeded, simply having the default closerule of Y will generate some small amounts of overhead for this address space.