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 '1996-12-01'
	and l_shipdate < cast(date '1996-12-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1167159.66..1167159.67 rows=1 width=29) (actual time=7418.613..7418.613 rows=1 loops=1)
   Buffers: shared hit=179581 read=277763 written=9996
   ->  Hash Join  (cost=101726.51..1153753.91 rows=766043 width=29) (actual time=2032.916..7023.466 rows=772405 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=179581 read=277763 written=9996
         ->  Bitmap Heap Scan on lineitem  (cost=16204.51..1056741.26 rows=766043 width=12) (actual time=492.141..4760.273 rows=772405 loops=1)
               Recheck Cond: ((l_shipdate >= '1996-12-01'::date) AND (l_shipdate < '1997-01-01'::date))
               Heap Blocks: exact=414703
               Buffers: shared hit=163706 read=253113 written=8826
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16013.00 rows=766043 width=0) (actual time=335.824..335.824 rows=777349 loops=1)
                     Index Cond: ((l_shipdate >= '1996-12-01'::date) AND (l_shipdate < '1997-01-01'::date))
                     Buffers: shared hit=184 read=1932 written=80
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1532.387..1532.387 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=15872 read=24650 written=1170
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.016..853.706 rows=2000000 loops=1)
                     Buffers: shared hit=15872 read=24650 written=1170
 Planning time: 3.129 ms
 Execution time: 7421.608 ms
(19 rows)

COMMIT;
COMMIT