The Copy From Import File (CPYFRMIMPF) supports copying the data in parallel from an import file to a to-file using multiple jobs during the copy. This allows you to copy data files from other platforms into a to-file quickly and easily. This is especially useful for those who use data warehousing. To use multiple jobs, your server must have the Symmetric Multiprocessing Product (SMP).
The number of jobs you use during the copy is determined by the DEGREE(*NBRTASKS) parameter of the Change Query Attributes (CHGQRYA) command. If the from-file has less than 50,000 records, only one job will be used regardless of the *NBRTASKS value.
The CPYFRMIMPF command (with the parallel data loader support) essentially breaks the import file into smaller portions or blocks. Each of these smaller portions is submitted in parallel, so the entire file processes at the same time. (This eliminates the latency of sequential processing.)
To maintain the same relative record numbers of the from-file in the to-file, use only one job for the copy. Specify DEGREE(*NONE).
Records are not copied in parallel when the from stream
file (FROMSTMF) parameter is specified.