Allocating storage for sort or merge operations

Certain parameters set during the installation of DFSORT determine the amount of storage that DFSORT uses. In general, the more storage DFSORT has available, the faster the sort or merge operations in your program will be.

DFSORT installation should not allocate all the free space in the region for its COBOL operation, however. When your program is running, storage must be available for:

• COBOL programs that are dynamically called from an input or output procedure
• Language Environment® runtime library modules
• Data management modules that can be loaded into the region for use by an input or output procedure
• Any storage obtained by these modules

For a specific sort or merge operation, you can override the DFSORT storage values set at installation. To do so, code the MAINSIZE and RESINV keywords on the OPTION control statement in the sort control statement data set, or use the SORT-CORE-SIZE special register.

Be careful not to override the storage allocation to the extent that all the free space in the region is used for sort operations for your COBOL program.