Full_Description

   Sort obtains the file's longest record length (LRL) and file size
   from RMS. If you know the LRL that RMS has defined for the input
   files is incorrect, you can override this value by specifying the
   record size with RECORD_SIZE. For multiple input files, LRL is
   the length of the longest record in all files.

   If you do not know the LRL value for a file, use the ANALYZE/RMS_
   FILE command. The LRL value appears in the file attributes
   section in the statistical report generated for the file that
   you specify.

   Sort uses input file size information to determine the amount
   of memory needed, as well as the size of the work files for the
   sort operation. If the file size is unknown (for example, you
   are sorting files not residing on disk or standard ANSI magnetic
   tape), Sort assumes a fairly large file size.

   If this default is too large, Sort overestimates its memory and
   work file requirements; the sort operation will be more efficient
   if you specify a smaller input file size. If the default is too
   small, Sort underestimates its memory requirements; therefore,
   you should specify a larger input file size, provided the Sort
   data structure size is not limited by the working set extent.