@Override
  protected HiveDecimalWritable computeValue(HiveDecimalWritable number) {
    return VectorPTFEvaluatorHelper.computeValue(number);
  }
This class evaluates HiveDecimal sum() for a PTF group.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/ptf/VectorPTFEvaluatorDecimalSum.java