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 '1994-04-01'
	and l_shipdate < cast(date '1994-04-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1179674.47..1179674.48 rows=1 width=29) (actual time=8085.218..8085.219 rows=1 loops=1)
   Buffers: shared hit=215260 read=236528 written=119
   ->  Hash Join  (cost=102065.47..1165949.52 rows=784283 width=29) (actual time=2490.201..7692.653 rows=747587 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=215260 read=236528 written=119
         ->  Bitmap Heap Scan on lineitem  (cost=16543.47..1068663.27 rows=784283 width=12) (actual time=713.397..5159.638 rows=747587 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-04-01'::date) AND (l_shipdate < '1994-05-01'::date))
               Heap Blocks: exact=409218
               Buffers: shared hit=213274 read=197989 written=80
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16347.40 rows=784283 width=0) (actual time=541.893..541.893 rows=755762 loops=1)
                     Index Cond: ((l_shipdate >= '1994-04-01'::date) AND (l_shipdate < '1994-05-01'::date))
                     Buffers: shared hit=2 read=2043
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1762.382..1762.382 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=1983 read=38539 written=39
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.020..1043.896 rows=2000000 loops=1)
                     Buffers: shared hit=1983 read=38539 written=39
 Planning time: 4.516 ms
 Execution time: 8090.919 ms
(19 rows)

COMMIT;
COMMIT