static uint32 get_next_subpartition_via_walking(PARTITION_ITERATOR *part_iter)
{
  Field *field= part_iter->part_info->subpart_field_array[0];
  uint32 res;
  if (part_iter->field_vals.cur == part_iter->field_vals.end)
  {
    part_iter->field_vals.cur= part_iter->field_vals.start;
    return NOT_A_PARTITION_ID;
  }
  field->store(part_iter->field_vals.cur++, field->flags & UNSIGNED_FLAG);
  if (part_iter->part_info->get_subpartition_id(part_iter->part_info,
                                                &res))
    return NOT_A_PARTITION_ID;
  return res;
}
static uint32 get_next_subpartition_via_walking(PARTITION_ITERATOR *part_iter)
{
  Field *field= part_iter->part_info->subpart_field_array[0];
  uint32 res;
  if (part_iter->field_vals.cur == part_iter->field_vals.end)
  {
    part_iter->field_vals.cur= part_iter->field_vals.start;
    return NOT_A_PARTITION_ID;
  }
  field->store(part_iter->field_vals.cur++, field->flags & UNSIGNED_FLAG);
  if (part_iter->part_info->get_subpartition_id(part_iter->part_info,
                                                &res))
    return NOT_A_PARTITION_ID;
  return res;
}