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=1185667.27..1185667.28 rows=1 width=29) (actual time=12497.460..12497.460 rows=1 loops=1)
   Buffers: shared hit=314406 read=141519 dirtied=415 written=32
   ->  Hash Join  (cost=102506.06..1171651.50 rows=800901 width=29) (actual time=4304.745..12011.842 rows=774678 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=314406 read=141519 dirtied=415 written=32
         ->  Bitmap Heap Scan on lineitem  (cost=16984.06..1068109.23 rows=800901 width=12) (actual time=1372.214..5871.251 rows=774678 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-08-01'::date) AND (l_shipdate < '1994-09-01'::date))
               Buffers: shared hit=300870 read=114530 dirtied=415 written=32
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16783.84 rows=800901 width=0) (actual time=1099.927..1099.927 rows=775452 loops=1)
                     Index Cond: ((l_shipdate >= '1994-08-01'::date) AND (l_shipdate < '1994-09-01'::date))
                     Buffers: shared hit=1171 read=949
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2930.545..2930.545 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=13533 read=26989
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.015..1129.395 rows=2000000 loops=1)
                     Buffers: shared hit=13533 read=26989
 Total runtime: 12534.122 ms
(17 rows)

COMMIT;
COMMIT