@Override
    public void write(Kryo kryo, Output output, Path path) {
      output.writeString(path.toUri().toString());
    }
Custom Kryo serializer for sql date, otherwise Kryo gets confused between
java.sql.Date and java.util.Date while deserializing
ql/src/java/org/apache/hadoop/hive/ql/exec/SerializationUtilities.java