This variable sets the number of temporary files used by SORT. The acceptable
range is from 4 to 32. (The maximum is 16 for the regular MS-DOS runtime.)
The default value is "4".
Increasing the number of files used usually improves SORT performance,
particularly for large sorts. Note that you must have enough available file handles
to open all of the temporary files concurrently. In general, the number of
files available is more important than the amount of memory used. If you are
experiencing long sorts, try increasing the number of files before you increase the
amount of sort memory.
The SORT verb removes all of its temporary files, except for one, prior to
beginning its output phase.