Item_sum_variance::Item_sum_variance(THD *thd, Item_sum_variance *item):
  Item_sum_num(thd, item),
    count(item->count), sample(item->sample),
    prec_increment(item->prec_increment)
{
  recurrence_m= item->recurrence_m;
  recurrence_s= item->recurrence_s;
}
Item_sum_variance::Item_sum_variance(THD *thd, Item_sum_variance *item):
  Item_sum_num(thd, item),
    count(item->count), sample(item->sample),
    prec_increment(item->prec_increment)
{
  recurrence_m= item->recurrence_m;
  recurrence_s= item->recurrence_s;
}