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 '1996-01-01'
	and l_shipdate < cast(date '1996-01-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1168501.23..1168501.24 rows=1 width=29) (actual time=27229.861..27229.861 rows=1 loops=1)
   Buffers: shared hit=186544 read=268446
   ->  Hash Join  (cost=101706.47..1155147.21 rows=763087 width=29) (actual time=5308.420..26547.435 rows=772594 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=186544 read=268446
         ->  Bitmap Heap Scan on lineitem  (cost=16184.47..1052455.75 rows=763087 width=12) (actual time=976.226..18332.929 rows=772594 loops=1)
               Recheck Cond: ((l_shipdate >= '1996-01-01'::date) AND (l_shipdate < '1996-02-01'::date))
               Buffers: shared hit=169849 read=244616
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15993.70 rows=763087 width=0) (actual time=684.736..684.736 rows=773370 loops=1)
                     Index Cond: ((l_shipdate >= '1996-01-01'::date) AND (l_shipdate < '1996-02-01'::date))
                     Buffers: shared hit=1 read=2113
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=4328.887..4328.887 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=16692 read=23830
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.022..3129.362 rows=2000000 loops=1)
                     Buffers: shared hit=16692 read=23830
 Total runtime: 27262.829 ms
(17 rows)

COMMIT;
COMMIT