BEGIN;
BEGIN
select
	100.00 * sum(case
		when p_type like 'PROMO%'
			then l_extendedprice * (1 - l_discount)
		else 0
	end) / sum(l_extendedprice * (1 - l_discount)) as promo_revenue
from
	lineitem,
	part
where
	l_partkey = p_partkey
	and l_shipdate >= date '1993-06-01'
	and l_shipdate < cast(date '1993-06-01' + interval '1 month' as date);
 promo_revenue  
----------------
 16.66378584879
(1 row)

COMMIT;
COMMIT