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 '1997-01-01'
	and l_shipdate < cast(date '1997-01-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1174797.55..1174797.57 rows=1 width=29) (actual time=16899.214..16899.214 rows=1 loops=1)
   Buffers: shared hit=234062 read=223127 dirtied=8 written=16715
   ->  Hash Join  (cost=101766.97..1161353.89 rows=768209 width=29) (actual time=3991.077..16260.999 rows=772310 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=234062 read=223127 dirtied=8 written=16715
         ->  Bitmap Heap Scan on lineitem  (cost=16244.97..1058547.19 rows=768209 width=12) (actual time=988.201..10450.944 rows=772310 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-01-01'::date) AND (l_shipdate < '1997-02-01'::date))
               Buffers: shared hit=227622 read=189042 dirtied=8 written=13795
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16052.92 rows=768209 width=0) (actual time=734.816..734.816 rows=778201 loops=1)
                     Index Cond: ((l_shipdate >= '1997-01-01'::date) AND (l_shipdate < '1997-02-01'::date))
                     Buffers: shared hit=344 read=1772 written=37
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=3001.084..3001.084 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=6437 read=34085 written=2920
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.013..1848.989 rows=2000000 loops=1)
                     Buffers: shared hit=6437 read=34085 written=2920
 Total runtime: 16910.751 ms
(17 rows)

COMMIT;
COMMIT