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 '1994-09-01'
	and l_shipdate < cast(date '1994-09-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1177593.07..1177593.08 rows=1 width=29) (actual time=7639.413..7639.413 rows=1 loops=1)
   Buffers: shared hit=222425 read=229183 dirtied=163 written=468
   ->  Hash Join  (cost=102091.82..1163864.09 rows=784513 width=29) (actual time=2313.960..7253.018 rows=750479 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=222425 read=229183 dirtied=163 written=468
         ->  Bitmap Heap Scan on lineitem  (cost=16569.82..1066574.40 rows=784513 width=12) (actual time=547.306..4431.130 rows=750479 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-09-01'::date) AND (l_shipdate < '1994-10-01'::date))
               Heap Blocks: exact=409030
               Buffers: shared hit=216527 read=194556 dirtied=163 written=408
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16373.70 rows=784513 width=0) (actual time=362.276..362.276 rows=756787 loops=1)
                     Index Cond: ((l_shipdate >= '1994-09-01'::date) AND (l_shipdate < '1994-10-01'::date))
                     Buffers: shared read=2053 written=4
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1749.751..1749.751 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=5895 read=34627 written=60
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.011..917.142 rows=2000000 loops=1)
                     Buffers: shared hit=5895 read=34627 written=60
 Planning time: 3.642 ms
 Execution time: 7646.318 ms
(19 rows)

COMMIT;
COMMIT