protected void forward(Object row, ObjectInspector rowInspector)
      throws HiveException {
    runTimeNumRows++;
    if (getDone()) {
      return;
    }

    int childrenDone = 0;
    for (int i = 0; i < childOperatorsArray.length; i++) {
      Operator<? extends OperatorDesc> o = childOperatorsArray[i];
      if (o.getDone()) {
        childrenDone++;
      } else {
        o.process(row, childOperatorsTag[i]);
      }
    }

    // if all children are done, this operator is also done
    if (childrenDone != 0 && childrenDone == childOperatorsArray.length) {
      setDone(true);
    }
  }
Replace one parent with another at the same position. Chilren of the new
parent are not updated

@param parent
         the old parent
@param newParent
         the new parent
ql/src/java/org/apache/hadoop/hive/ql/exec/Operator.java