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 '1994-08-01'
	and l_shipdate < cast(date '1994-08-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1172710.79..1172710.80 rows=1 width=29) (actual time=11757.229..11757.230 rows=1 loops=1)
   Buffers: shared hit=159209 read=298801 dirtied=32 written=12285
   ->  Hash Join  (cost=101692.97..1159332.00 rows=764502 width=29) (actual time=2296.144..11275.712 rows=774032 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=159209 read=298801 dirtied=32 written=12285
         ->  Bitmap Heap Scan on lineitem  (cost=16170.97..1056608.71 rows=764502 width=12) (actual time=650.750..6704.579 rows=774032 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-08-01'::date) AND (l_shipdate < '1994-09-01'::date))
               Buffers: shared hit=155994 read=261491 dirtied=32 written=12197
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15979.85 rows=764502 width=0) (actual time=403.255..403.255 rows=779409 loops=1)
                     Index Cond: ((l_shipdate >= '1994-08-01'::date) AND (l_shipdate < '1994-09-01'::date))
                     Buffers: shared read=2120
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1643.545..1643.545 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=3212 read=37310 written=88
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.011..944.030 rows=2000000 loops=1)
                     Buffers: shared hit=3212 read=37310 written=88
 Total runtime: 11772.753 ms
(17 rows)

COMMIT;
COMMIT