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 '1997-09-01'
	and l_shipdate < cast(date '1997-09-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1181444.22..1181444.24 rows=1 width=29) (actual time=36260.414..36260.414 rows=1 loops=1)
   Buffers: shared hit=225058 read=228022 dirtied=30 written=114
   ->  Hash Join  (cost=101841.26..1167901.04 rows=773896 width=29) (actual time=5485.523..35481.263 rows=749165 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=225058 read=228022 dirtied=30 written=114
         ->  Bitmap Heap Scan on lineitem  (cost=16319.26..1064966.38 rows=773896 width=12) (actual time=1192.951..26800.814 rows=749165 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-09-01'::date) AND (l_shipdate < '1997-10-01'::date))
               Buffers: shared hit=202667 read=209888 dirtied=30 written=52
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16125.79 rows=773896 width=0) (actual time=929.767..929.767 rows=758214 loops=1)
                     Index Cond: ((l_shipdate >= '1997-09-01'::date) AND (l_shipdate < '1997-10-01'::date))
                     Buffers: shared hit=3 read=2047
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=4290.885..4290.885 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=22388 read=18134 written=62
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.019..3005.990 rows=2000000 loops=1)
                     Buffers: shared hit=22388 read=18134 written=62
 Total runtime: 36374.598 ms
(17 rows)

COMMIT;
COMMIT