Of the orders with a lower delivery priority, how many have an urgent priority order?
an urgent priority order refers to o_orderkey where o_orderpriority = '1-URGENT'; earlier orderdate have higher priority in delivery; lower delivery priority refers to MAX(o_orderdate);
SELECT COUNT(o_orderkey) FROM orders WHERE o_orderpriority = '1-URGENT' GROUP BY o_orderdate ORDER BY o_orderdate DESC LIMIT 1