Initialization Best Practices › Make 64-bit Memory Available to MUF Region

Make 64-bit Memory Available to MUF Region

Verify that your MUF batch job or started task allows the use of 64-bit memory.

Business Value

The 64-bit memory feature provides additional significant memory to z/OS regions making memory-resident processing much more available. Using memory-resident processing can greatly reduce physical I/O within the database region and can reduce CPU usage.

The Memory Resident Data Facility was enhanced to attempt to place VIRTUAL and COVERED areas into 64-bit memory. If the memory allocation does not fit in 64-bit memory, the MRDF allocations are placed into 31-bit data spaces.

MRDF COVERED data sets can significantly improve MUF request processing. For example, one user site employed MRDF COVERED processing on several high-use data sets. They were able to document a 40 percent reduction in I/O which delivered a 15 percent reduction in CPU consumption per request.

Additional Considerations

The 64-bit memory option is specified in the region parameter in your JCL. However, your site can have certain limitations on 64-bit memory set across your LPAR. Before implementing the change to add 64-bit memory, consult with your systems programming team.