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 '1994-08-01'
	and l_shipdate < cast(date '1994-08-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1179230.83..1179230.85 rows=1 width=29) (actual time=7202.889..7202.889 rows=1 loops=1)
   Buffers: shared hit=264761 read=193248 written=9
   ->  Hash Join  (cost=102258.85..1165380.60 rows=791442 width=29) (actual time=2338.896..6822.808 rows=774785 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=264761 read=193248 written=9
         ->  Bitmap Heap Scan on lineitem  (cost=16736.85..1067986.97 rows=791442 width=12) (actual time=810.853..4566.188 rows=774785 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-08-01'::date) AND (l_shipdate < '1994-09-01'::date))
               Heap Blocks: exact=415365
               Buffers: shared hit=237564 read=179920
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16538.98 rows=791442 width=0) (actual time=593.216..593.216 rows=779409 loops=1)
                     Index Cond: ((l_shipdate >= '1994-08-01'::date) AND (l_shipdate < '1994-09-01'::date))
                     Buffers: shared read=2119
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1455.909..1455.909 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=27194 read=13328 written=9
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.013..771.202 rows=2000000 loops=1)
                     Buffers: shared hit=27194 read=13328 written=9
 Planning time: 3.330 ms
 Execution time: 7207.032 ms
(19 rows)

COMMIT;
COMMIT