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 '1997-04-01'
	and l_shipdate < cast(date '1997-04-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1167187.90..1167187.92 rows=1 width=29) (actual time=13157.427..13157.427 rows=1 loops=1)
   Buffers: shared hit=315019 read=139623 written=98
   ->  Hash Join  (cost=101154.59..1154202.46 rows=742025 width=29) (actual time=3768.933..12560.299 rows=751150 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=315019 read=139623 written=98
         ->  Bitmap Heap Scan on lineitem  (cost=15632.59..1051984.90 rows=742025 width=12) (actual time=866.454..6234.595 rows=751150 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-04-01'::date) AND (l_shipdate < '1997-05-01'::date))
               Buffers: shared hit=315014 read=99103
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15447.08 rows=742025 width=0) (actual time=649.903..649.903 rows=761325 loops=1)
                     Index Cond: ((l_shipdate >= '1997-04-01'::date) AND (l_shipdate < '1997-05-01'::date))
                     Buffers: shared hit=2 read=2052
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2900.354..2900.354 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=2 read=40520 written=98
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.011..1701.510 rows=2000000 loops=1)
                     Buffers: shared hit=2 read=40520 written=98
 Total runtime: 13198.213 ms
(17 rows)

COMMIT;
COMMIT