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 '1997-12-01'
	and l_shipdate < cast(date '1997-12-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1167422.36..1167422.38 rows=1 width=29) (actual time=33362.474..33362.474 rows=1 loops=1)
   Buffers: shared hit=111751 read=342568 written=12493
   ->  Hash Join  (cost=101698.62..1154081.75 rows=762321 width=29) (actual time=3476.856..32590.690 rows=771764 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=111751 read=342568 written=12493
         ->  Bitmap Heap Scan on lineitem  (cost=16176.62..1051407.52 rows=762321 width=12) (actual time=1012.570..27103.452 rows=771764 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-12-01'::date) AND (l_shipdate < '1998-01-01'::date))
               Buffers: shared hit=71226 read=342568 written=12493
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15986.04 rows=762321 width=0) (actual time=812.243..812.243 rows=772591 loops=1)
                     Index Cond: ((l_shipdate >= '1997-12-01'::date) AND (l_shipdate < '1998-01-01'::date))
                     Buffers: shared hit=3 read=2111
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2462.557..2462.557 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=40522
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.015..1442.608 rows=2000000 loops=1)
                     Buffers: shared hit=40522
 Total runtime: 33381.963 ms
(17 rows)

COMMIT;
COMMIT