DASD contention due to I/O on DEDBs

As always, I/O contention for DEDB Areas will act as a limitation upon performance.

To minimize this impact:

Limit the number of heavily-used Areas per device.
Limit the number of application programs accessing any one DEDB area. One possibility here is to design the transaction, input edit/routing exit, and randomizing algorithm combination so that the access to any one area is limited to a particular application program or programs.
Limit the incidence and effect of stealing unmodified buffers by appropriate application program design. Buffer stealing can necessitate a second I/O to recover the stolen buffer/control interval. This can happen if the logic of the application program requires processing of a buffer when a significant number of calls have been made following the first retrieval.