with quantity_sales as(
    select max(quantity) as max_quantity,
        prod_id
    from (
        select prod_id, 
            time_id, 
            sum(quantity_sold) as quantity
        from sh.sales
        group by prod_id, time_id
        order by quantity desc, prod_id asc)
    group by prod_id
    order by 1 desc)
select max_quantity as "Макс покуп/день",
    prod_name
from quantity_sales
join sh.products using (prod_id)
where rownum <= 20
;