BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
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 '1993-03-01'
	and l_shipdate < cast(date '1993-03-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1182926.07..1182926.08 rows=1 width=29) (actual time=21014.204..21014.204 rows=1 loops=1)
   Buffers: shared hit=323370 read=134882
   ->  Hash Join  (cost=102158.02..1169163.05 rows=786458 width=29) (actual time=3405.031..20294.712 rows=775107 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=323370 read=134882
         ->  Bitmap Heap Scan on lineitem  (cost=16636.02..1065945.75 rows=786458 width=12) (actual time=926.333..14611.706 rows=775107 loops=1)
               Recheck Cond: ((l_shipdate >= '1993-03-01'::date) AND (l_shipdate < '1993-04-01'::date))
               Buffers: shared hit=285607 read=132120
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16439.41 rows=786458 width=0) (actual time=721.822..721.822 rows=779610 loops=1)
                     Index Cond: ((l_shipdate >= '1993-03-01'::date) AND (l_shipdate < '1993-04-01'::date))
                     Buffers: shared hit=2 read=2118
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2476.544..2476.544 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=37760 read=2762
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.017..1462.652 rows=2000000 loops=1)
                     Buffers: shared hit=37760 read=2762
 Total runtime: 21030.511 ms
(17 rows)

COMMIT;
COMMIT