HP 3000 Manual page 17

with XSORTIN1.
When you use more than one input file:
• You cannot do an Address-out (SORTA) sort.
• You cannot do an in place sort, in which output file overlays input
• XSORT bases its operations on the characteristics of the first file
sumed to have the same, or
• You must be sure that all your specifications apply to all the records in all the files you wish to use in a
multifile sort.
• You can ensure that you do not accidentally do a single-file sort (instead of a multiple-file sort) by issuing
the following MPE command prior to running your XSORT program:
RESET XSORTIN
(See "Use of the MPE RESET Command.")
If single file input is from $STDIN, the specification records cannot be from $STDIN. They must be from a
file referenced by the formal designator XSORTEXT.
Work Space
• XSORT tells SORT how much work space will be required for performing the actual sort. For single-file
input from disk, it determines the space needed to sort by the number of records in the input file. You
can directly supply this number by specifying the "maximum numbers of records to be sorted", using the
S Option (See Section 4). This must be done in the following two cases:
• Single-file non-disk input--including $STDIN.
• Multiple-file input.
If only a small percentage of the records from a single-file sort are being selected and sorted, XSORT will
make more efficient use of resources if a reasonably accurate "maximum number of records to be sorted" is
specified using the S Option.
Output File
The output file is your sorted file. It can be a sequential MPE file or an already existing KSAM file. The
output can be given in one of three formats:
• Address-out.
• Record-out.
• Count-only. (No output file is produced. XSORT only prints sort statistics.)
The formal file designator is XSORTOUT.
If XSORTOUT does not already exist (non-disk files by definition already exist) then XSORT will create it
as a job temporary disk file. If XSORTOUT does already exist, then it must be the same file as XSORTIN.
In such an instance, the sort is an in place sort. (This requirement can be overridden by coding a "Y" in
column 8 of the S Option specs to allow output to an existing file other than XSORTIN.) XSORTOUT can
never be the same as any of the XSORTIN1 through XSORTIN9 files in a multiple-file sort.
compatible, characteristics (file type and record length).
file.
opened. All the other files are as-
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