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 '1994-05-01'
	and l_shipdate < cast(date '1994-05-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1195364.39..1195364.41 rows=1 width=29) (actual time=17852.084..17852.084 rows=1 loops=1)
   Buffers: shared hit=167346 read=292944 dirtied=135 written=24815
   ->  Hash Join  (cost=102420.66..1181330.53 rows=801935 width=29) (actual time=5418.464..17219.580 rows=772815 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=167346 read=292944 dirtied=135 written=24815
         ->  Bitmap Heap Scan on lineitem  (cost=16898.66..1077764.99 rows=801935 width=12) (actual time=928.349..9266.344 rows=772815 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-05-01'::date) AND (l_shipdate < '1994-06-01'::date))
               Buffers: shared hit=167341 read=252424 dirtied=135 written=24164
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16698.18 rows=801935 width=0) (actual time=637.623..637.623 rows=784221 loops=1)
                     Index Cond: ((l_shipdate >= '1994-05-01'::date) AND (l_shipdate < '1994-06-01'::date))
                     Buffers: shared hit=452 read=1665
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=4488.632..4488.632 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=2 read=40520 written=651
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.014..2309.200 rows=2000000 loops=1)
                     Buffers: shared hit=2 read=40520 written=651
 Total runtime: 17882.794 ms
(17 rows)

COMMIT;
COMMIT