UOW locking

In a globally shared environment, data is shared not only between IMS subsystems, but also across central processor complexes (CPC).

In such an environment, communication between two IRLMs could potentially bottleneck and become impeded. To ease this problem, HSSP locks at a UOW level in update mode, reducing the locking overhead. Non-HSSP or DEDB online processing locks at a UOW level in a shared mode. Otherwise, the locking for DEDB online processing is at the CI level. For information on UOW locking, refer to IMS Version 15.5 System Administration.