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 '1997-05-01'
	and l_shipdate < cast(date '1997-05-01' + interval '1 month' as date);
                                                                                QUERY PLAN                                                                                 
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1182143.00..1182143.02 rows=1 width=29) (actual time=19227.491..19227.491 rows=1 loops=1)
   Buffers: shared hit=337476 read=118550 dirtied=277 written=14
   ->  Hash Join  (cost=102335.58..1168268.06 rows=792854 width=29) (actual time=7537.734..18619.298 rows=774552 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=337476 read=118550 dirtied=277 written=14
         ->  Bitmap Heap Scan on lineitem  (cost=16813.58..1064906.84 rows=792854 width=12) (actual time=4863.408..12590.880 rows=774552 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-05-01'::date) AND (l_shipdate < '1997-06-01'::date))
               Buffers: shared hit=296951 read=118550 dirtied=277 written=14
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16615.37 rows=792854 width=0) (actual time=4657.472..4657.472 rows=775346 loops=1)
                     Index Cond: ((l_shipdate >= '1997-05-01'::date) AND (l_shipdate < '1997-06-01'::date))
                     Buffers: shared hit=4 read=2115 written=2
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2672.500..2672.500 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=40522
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.013..1330.598 rows=2000000 loops=1)
                     Buffers: shared hit=40522
 Total runtime: 19251.837 ms
(17 rows)

COMMIT;
COMMIT