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 '1995-10-01'
	and l_shipdate < cast(date '1995-10-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1183001.34..1183001.35 rows=1 width=29) (actual time=19438.794..19438.794 rows=1 loops=1)
   Buffers: shared hit=197653 read=261441 written=209
   ->  Hash Join  (cost=101994.91..1169346.07 rows=780301 width=29) (actual time=4438.739..18747.607 rows=774201 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=197653 read=261441 written=209
         ->  Bitmap Heap Scan on lineitem  (cost=16472.91..1066267.30 rows=780301 width=12) (actual time=1021.739..11688.095 rows=774201 loops=1)
               Recheck Cond: ((l_shipdate >= '1995-10-01'::date) AND (l_shipdate < '1995-11-01'::date))
               Buffers: shared hit=181962 read=236607 written=209
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16277.84 rows=780301 width=0) (actual time=734.300..734.300 rows=781910 loops=1)
                     Index Cond: ((l_shipdate >= '1995-10-01'::date) AND (l_shipdate < '1995-11-01'::date))
                     Buffers: shared read=2119
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=3414.850..3414.850 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=15688 read=24834
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.012..1683.787 rows=2000000 loops=1)
                     Buffers: shared hit=15688 read=24834
 Total runtime: 19464.349 ms
(17 rows)

COMMIT;
COMMIT