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 '1997-09-01'
	and l_shipdate < cast(date '1997-09-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1169357.30..1169357.31 rows=1 width=29) (actual time=7623.297..7623.297 rows=1 loops=1)
   Buffers: shared hit=195545 read=257132 dirtied=380 written=256
   ->  Hash Join  (cost=101593.87..1156020.92 rows=762079 width=29) (actual time=2644.649..7244.087 rows=749172 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=195545 read=257132 dirtied=380 written=256
         ->  Bitmap Heap Scan on lineitem  (cost=16071.87..1059067.73 rows=762079 width=12) (actual time=592.460..4471.565 rows=749172 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-09-01'::date) AND (l_shipdate < '1997-10-01'::date))
               Heap Blocks: exact=410103
               Buffers: shared hit=195294 read=216858 dirtied=380 written=242
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15881.36 rows=762079 width=0) (actual time=393.381..393.381 rows=757483 loops=1)
                     Index Cond: ((l_shipdate >= '1997-09-01'::date) AND (l_shipdate < '1997-10-01'::date))
                     Buffers: shared read=2049
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1621.382..1621.382 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=248 read=40274 written=14
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.016..917.834 rows=2000000 loops=1)
                     Buffers: shared hit=248 read=40274 written=14
 Planning time: 3.371 ms
 Execution time: 7630.248 ms
(19 rows)

COMMIT;
COMMIT