Introduction

When a sort application cannot be performed entirely in virtual storage, DFSORT must use work space. The amount of work space required depends on:

The amount of data being sorted
The amount of virtual storage available to DFSORT
The amount of Hiperspace available to DFSORT
The type of devices you use
The DFSORT functions and features you use (for example, VLSHRT, locale processing, EFS, and ALTSEQ can increase the amount of work space required).

There are three ways to supply work space for a DFSORT application:

Hiperspace
Dynamic allocation of work data sets
JCL allocation of work data sets.

For best performance, an optimal amount of Hiperspace, in combination with dynamically allocated disk work data sets, is strongly recommended. See Use Hipersorting for more information on using the HIPRMAX option. The DYNAUTO installation option, or the DYNALLOC run-time option, can be used to dynamically allocate work data sets.