I have a JSON dataset and need to create a unique key from it. No single field is unique, but the first two, together, are. What I want to convert from:   [{"airport":"KDEN", "runway":"16R", "length":16000}, ...]   and I want to concatenate the "airport" and "runway" values to create this:   [{"key":"KDEN/16R", "airport":"KDEN", "runway":"16R", "length":16000}, ...]   I've got it working with an ugly anti-pattern of SplitRecord, EvaluateJSONPath, UpdateAttribute, and AttributesToJSON  which changes each flow file to several thousand, but am looking for a better way to do this.  ... View more