FastSort Manual

Using FastSort Commands
FastSort Manual—429834-003
3-20
RUN Command
volume. For more information about scratch files and scratch volumes, see
Managing Sort Workspace on page 9-1.
AUTOMATIC
directs FastSort to limit elapsed time by using at most 50 percent (90 percent in
parallel sorting) of the physical memory not locked down by the operating system.
For files equal to or smaller than 100 KB, FastSort uses 256 pages for an extended
memory segment and makes no merge pass. For larger files, FastSort attempts to
use enough memory to make only one merge pass. If you do not specify the
SEGMENT, MINSPACE, or MINTIME parameter, AUTOMATIC is the default.
The file size is the maximum number of records in all input files times the
maximum record length for the output file. For more information, see the
description of the FROM Command on page 3-14. For details about the amount of
memory required to make only one merge pass for different file sizes, see
Controlling Extended Memory on page 2-11.
If you specify AUTOMATIC, do not specify MINSPACE, MINTIME, or SEGMENT. If
you specify one of these parameters with AUTOMATIC, FastSort ignores the
parameter and returns a warning message.
If you specify AUTOMATIC for a distributor-collector process for parallel sorting, all
of the subsort processes use AUTOMATIC, unless you override it with the
SEGMENT parameter of the SUBSORT command or a SUBSORT DEFINE.
BLOCK size
specifies the size, in bytes, of input and output blocks for scratch files. The scratch
file block size must be large enough to accept the largest input record, rounded up
to the nearest even byte, plus 14 bytes of overhead.
The block size can be any multiple of 2048 up to 56 KB. The default is 56 KB.
CPU processor
specifies the processor (CPU) number in which the SORTPROG process should
run. Because SORTPROG is a separate process, you can run it in a different
processor from the one in which the SORT process is running. The default is the
same processor.
MEM memory
exists only for compatibility with earlier sort-merge code. MEM specifies the
number of memory pages allocated for the SORTPROG process. The size is
always 64 pages. If you specify a value between 1 and 64 for MEM, FastSort
ignores the value. If you specify an invalid value, FastSort returns an error
message and does not start the sort or merge run.