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 '1995-09-01'
	and l_shipdate < cast(date '1995-09-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1177106.41..1177106.42 rows=1 width=29) (actual time=16479.757..16479.757 rows=1 loops=1)
   Buffers: shared hit=126600 read=327733 written=156
   ->  Hash Join  (cost=101574.42..1163772.97 rows=761911 width=29) (actual time=3803.717..15791.703 rows=749681 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=126600 read=327733 written=156
         ->  Bitmap Heap Scan on lineitem  (cost=16052.42..1061107.97 rows=761911 width=12) (actual time=1047.985..9343.518 rows=749681 loops=1)
               Recheck Cond: ((l_shipdate >= '1995-09-01'::date) AND (l_shipdate < '1995-10-01'::date))
               Buffers: shared hit=126590 read=287218 written=118
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15861.94 rows=761911 width=0) (actual time=678.864..678.864 rows=760393 loops=1)
                     Index Cond: ((l_shipdate >= '1995-09-01'::date) AND (l_shipdate < '1995-10-01'::date))
                     Buffers: shared hit=2 read=2050
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2753.501..2753.501 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=7 read=40515 written=38
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.015..1431.429 rows=2000000 loops=1)
                     Buffers: shared hit=7 read=40515 written=38
 Total runtime: 16507.182 ms
(17 rows)

COMMIT;
COMMIT