Type_handler::aggregate_for_result_traditional(const Type_handler *a,
                                               const Type_handler *b)
{
  enum_field_types ta= a->real_field_type();
  enum_field_types tb= b->real_field_type();
  return
    Type_handler::get_handler_by_real_type(Field::field_type_merge(ta, tb));
}
Type_handler::aggregate_for_result_traditional(const Type_handler *a,
                                               const Type_handler *b)
{
  enum_field_types ta= a->real_field_type();
  enum_field_types tb= b->real_field_type();
  return
    Type_handler::get_handler_by_real_type(Field::field_type_merge(ta, tb));
}