@Override
  protected String getFuncName() {
    return "levenshtein";
  }
GenericUDFLevenshtein.

This function calculates the Levenshtein distance between two strings.
Levenshtein distance is a string metric for measuring the difference between
two sequences. Informally, the Levenshtein distance between two words is the
minimum number of single-character edits (i.e. insertions, deletions or
substitutions) required to change one word into the other. It is named after
Vladimir Levenshtein, who considered this distance in 1965
ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDFLevenshtein.java