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 '1994-10-01'
	and l_shipdate < cast(date '1994-10-01' + interval '1 month' as date);
                                                                                QUERY PLAN                                                                                 
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1172348.09..1172348.11 rows=1 width=29) (actual time=7635.277..7635.278 rows=1 loops=1)
   Buffers: shared hit=243268 read=212066 dirtied=421 written=8814
   ->  Hash Join  (cost=102110.65..1158648.43 rows=782838 width=29) (actual time=2550.218..7265.124 rows=771049 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=243268 read=212066 dirtied=421 written=8814
         ->  Bitmap Heap Scan on lineitem  (cost=16588.65..1061383.86 rows=782838 width=12) (actual time=1196.026..5193.048 rows=771049 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-10-01'::date) AND (l_shipdate < '1994-11-01'::date))
               Heap Blocks: exact=412698
               Buffers: shared hit=202743 read=212066 dirtied=421 written=8814
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16392.94 rows=782838 width=0) (actual time=1033.751..1033.751 rows=773270 loops=1)
                     Index Cond: ((l_shipdate >= '1994-10-01'::date) AND (l_shipdate < '1994-11-01'::date))
                     Buffers: shared hit=390 read=1721 written=144
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1343.827..1343.827 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=40522
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.019..676.749 rows=2000000 loops=1)
                     Buffers: shared hit=40522
 Planning time: 2.410 ms
 Execution time: 7641.510 ms
(19 rows)

COMMIT;
COMMIT