The VSAMEMT option specifies the processing of empty VSAM data sets provided as input to a sort, merge, or copy.
If you specify VSAMEMT=YES, an empty VSAM data set will be processed as a legitimate data set containing 0 records, and MFX will end with a return code of 0.
The delivered default, VSAMEMT=NO, instructs MFX to terminate with a WER254A critical error if an empty VSAM data set is specified for input.