Use this field to specify the variables from the primary input data set by which to merge data from the secondary input data set.The same variables must exist in the Secondary Input Data Set. Only observations that have the same value(s) of the Merge Key Variables in both the Primary and Secondary Input Data Sets are carried through in the analysis.Note : The identity of the primary and secondary input data sets will vary with the process. The Input SAS Data Set is considered the primary input data set. The secondary input data set can include the Annotation SAS Data Set , a Coordinate Data Set , and so on.All of the variables in the specified input data set are displayed in the Available Variables field.
Click to add the highlighted variable(s) to the Merge Key Variables field, as shown below: