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 '1995-08-01'
	and l_shipdate < cast(date '1995-08-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1175238.59..1175238.60 rows=1 width=29) (actual time=9950.045..9950.045 rows=1 loops=1)
   Buffers: shared hit=211860 read=248062 written=114
   ->  Hash Join  (cost=101818.26..1161710.34 rows=773043 width=29) (actual time=2633.445..9527.592 rows=773779 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=211860 read=248062 written=114
         ->  Bitmap Heap Scan on lineitem  (cost=16296.26..1064592.69 rows=773043 width=12) (actual time=580.177..5983.398 rows=773779 loops=1)
               Recheck Cond: ((l_shipdate >= '1995-08-01'::date) AND (l_shipdate < '1995-09-01'::date))
               Heap Blocks: exact=417281
               Buffers: shared hit=211454 read=207943 written=102
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16103.00 rows=773043 width=0) (actual time=389.683..389.683 rows=783214 loops=1)
                     Index Cond: ((l_shipdate >= '1995-08-01'::date) AND (l_shipdate < '1995-09-01'::date))
                     Buffers: shared read=2116 written=3
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2040.461..2040.461 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=403 read=40119 written=12
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.018..1250.292 rows=2000000 loops=1)
                     Buffers: shared hit=403 read=40119 written=12
 Planning time: 3.476 ms
 Execution time: 9962.271 ms
(19 rows)

COMMIT;
COMMIT