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 '1995-12-01'
	and l_shipdate < cast(date '1995-12-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1168868.03..1168868.04 rows=1 width=29) (actual time=7149.425..7149.425 rows=1 loops=1)
   Buffers: shared hit=273284 read=184323 dirtied=347 written=415
   ->  Hash Join  (cost=101653.85..1155497.54 rows=764028 width=29) (actual time=2238.011..6768.541 rows=772148 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=273284 read=184323 dirtied=347 written=415
         ->  Bitmap Heap Scan on lineitem  (cost=16131.85..1058515.12 rows=764028 width=12) (actual time=552.705..4354.749 rows=772148 loops=1)
               Recheck Cond: ((l_shipdate >= '1995-12-01'::date) AND (l_shipdate < '1996-01-01'::date))
               Heap Blocks: exact=414970
               Buffers: shared hit=264799 read=152283 dirtied=347 written=361
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15940.84 rows=764028 width=0) (actual time=365.965..365.965 rows=779191 loops=1)
                     Index Cond: ((l_shipdate >= '1995-12-01'::date) AND (l_shipdate < '1996-01-01'::date))
                     Buffers: shared hit=1 read=2111 written=6
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1640.881..1640.881 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=8482 read=32040 written=54
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.018..966.403 rows=2000000 loops=1)
                     Buffers: shared hit=8482 read=32040 written=54
 Planning time: 2.896 ms
 Execution time: 7154.775 ms
(19 rows)

COMMIT;
COMMIT