Precedence rules for 64-bit memory allocation

Precedence rules govern the two IMS HP Change Accumulation Utility methods for using 64-bit memory.

• In single address space mode, the presence of HPCCACHE DD will take priority and 64-bit memory will be managed by the cache manager.
• IMS HP Change Accumulation Utility cache manager will indicate an out-of-memory condition to IMS HP Change Accumulation Utility when the lower of the two limits (HPCCACHE DD or MEMLIMIT in JCL) is reached.
• The MEMLIMIT control in the z/OS® JCL job card statement always takes precedence over any above the bar address space limit defined for IMS HP Change Accumulation Utility.
• If no MEMLIMIT is set at the system level (by whatever means), the system default is 0, meaning that this address space cannot use virtual storage above the bar.