Batch

The Batch Command Server, by default, and without explicit pre-allocation of work files, will attempt to allocate the work files dynamically during map execution.

Dynamic allocations incur a significant penalty compared to static pre-allocation of work files. Dynamic allocation inherits the overhead associated with the operating systems' dynamic allocation mechanisms. Therefore, pre-allocating work files before execution provides overall better performance.

A good guideline to use when pre-allocating work files is to allocate two temporary work files for each map card, plus one additional file. One of the two temporary work files for each card is used to process data sets containing variable-length records. The other temporary work file and the additional file are used as general-use work files.

See Temporary Data Sets (Work Files) for more details about allocating work files.