public int compareTo(Range other) {
    return getSize() == other.getSize() ? getStart() - other.getStart()
      : getSize() - other.getSize();
  }
When there are no parameters specified, partition iterator can be made faster;
In such cases, it need not materialize the ROW from RowContainer. This saves lots of IO.
ql/src/java/org/apache/hadoop/hive/ql/udf/ptf/Range.java