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 '1996-03-01'
	and l_shipdate < cast(date '1996-03-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1174201.37..1174201.38 rows=1 width=29) (actual time=9052.186..9052.186 rows=1 loops=1)
   Buffers: shared hit=209223 read=250000 dirtied=765 written=1195
   ->  Hash Join  (cost=101771.48..1160712.00 rows=770821 width=29) (actual time=2141.365..8646.638 rows=771605 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=209223 read=250000 dirtied=765 written=1195
         ->  Bitmap Heap Scan on lineitem  (cost=16249.48..1063627.68 rows=770821 width=12) (actual time=508.242..5701.105 rows=771605 loops=1)
               Recheck Cond: ((l_shipdate >= '1996-03-01'::date) AND (l_shipdate < '1996-04-01'::date))
               Heap Blocks: exact=416585
               Buffers: shared hit=185446 read=233252 dirtied=765 written=1174
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16056.77 rows=770821 width=0) (actual time=326.166..326.166 rows=781882 loops=1)
                     Index Cond: ((l_shipdate >= '1996-03-01'::date) AND (l_shipdate < '1996-04-01'::date))
                     Buffers: shared read=2113
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1510.287..1510.287 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=23774 read=16748 written=21
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.021..828.695 rows=2000000 loops=1)
                     Buffers: shared hit=23774 read=16748 written=21
 Planning time: 3.651 ms
 Execution time: 9059.537 ms
(19 rows)

COMMIT;
COMMIT