SORTMIn or SORTMInn DD statements are required to define the input to a multiple input application. A SORTIN DD statement will be ignored.
SORTMIn and SORTMInn data sets can be VSAM (entry-sequenced, key-sequenced or relative record) or non-VSAM data sets, including BatchPipes, z/OS pipes and HFS data sets. DCB information need not be supplied for a disk or standard labeled tape file. Any of the information accessed from a standard label can be overridden by coding the appropriate DCB parameter in the JCL.
It is possible to sort or copy up to 100 data sets. Each input data set is specified on a SORTMIn or SORTMInn DD statement. The valid range for n is 0 through 9; for nn, 00 through 99. If both SORTMIx and a SORTMI0x are specified, they are treated as duplicates and only the first definition is processed. Numbers may be skipped or used out of order. MFX will read the SORTMI files in numerical order. If EQUALS is in effect, the order of equal-keyed records within each SORTMInn file will be preserved. In addition, equal-keyed records from the lowest-numbered SORTMInn file will be written before those from the second SORTMInn file, and so on.
If no SORTMInn or SORTMIn data sets are defined when the “MULTIIN” PARM is passed, error message WER224A will be posted.
SORTMInn or SORTMIn cannot have concatenated input files. If a concatenation is present, error message WER509A will be issued.
The maximum record lengths supported are 32,760 bytes for fixed-length records and 32,767 bytes for variable-length records.
By default MFX does not accept an uninitialized SORTMInn data set and will terminate processing with a WER400A message. An uninitialized data set is one that has been newly created but never successfully closed. The UNINTDS PARM or installation option can be used to change MFX’s default mode of processing to accept an uninitialized input data set and process it as an empty file. See UNINTDS.
In the preceding example, SORTMI17 is a VSAM data set, SORTMI1 is a non-VSAM disk data set and SORTMI14 is a non-VSAM tape data set.