Hipersorting uses Hiperspace to improve the performance of sort applications that use DFSORT's Blockset Technique. A Hiperspace is a high-performance data space that resides in central storage and is backed by auxiliary storage when necessary. With Hipersorting, Hiperspace is used in place of and along with disk for temporary storage of records during a Blockset sort. Hipersorting reduces I/O processing, which in turn reduces elapsed time, EXCPs, and channel usage. Hipersorting is recommended when the input or output is a compressed sequential or VSAM data set.

You can control the maximum amount of Hiperspace for a Hipersorting application with the HIPRMAX parameter. HIPRMAX can direct DFSORT to dynamically determine the maximum amount of Hiperspace, subject to the available storage at the start of the run. You can also use HIPRMAX to suppress Hipersorting when optimizing CPU time is your major concern because Hipersorting can slightly degrade CPU time.

The actual amount of Hiperspace a Hipersorting application uses depends upon several factors. See the HIPRMAX description in OPTION control statement for more details. Most important, throughout the run, DFSORT determines the amount of available storage as well as the amount of storage needed by other concurrent Hipersorting, memory object sorting, and datapace sorting applications. Based on this information, DFSORT switches dynamically from using Hiperspace to using disk work data sets when either a storage shortage is predicted or the total Hipersorting, memory object sorting and dataspace sorting activity on the system reaches the limits set by the EXPMAX, EXPOLD, and EXPRES installation options. See z/OS DFSORT Installation and Customization for a complete description of these installation options.