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 '1997-07-01'
	and l_shipdate < cast(date '1997-07-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1185502.14..1185502.15 rows=1 width=29) (actual time=7355.260..7355.260 rows=1 loops=1)
   Buffers: shared hit=227135 read=232283 written=299
   ->  Hash Join  (cost=102384.93..1171518.59 rows=799060 width=29) (actual time=2149.065..6966.075 rows=774551 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=227135 read=232283 written=299
         ->  Bitmap Heap Scan on lineitem  (cost=16862.93..1074010.69 rows=799060 width=12) (actual time=512.909..4616.176 rows=774551 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-07-01'::date) AND (l_shipdate < '1997-08-01'::date))
               Heap Blocks: exact=416775
               Buffers: shared hit=227130 read=191763 written=231
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16663.16 rows=799060 width=0) (actual time=334.742..334.742 rows=782284 loops=1)
                     Index Cond: ((l_shipdate >= '1997-07-01'::date) AND (l_shipdate < '1997-08-01'::date))
                     Buffers: shared read=2118 written=5
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1625.240..1625.240 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=2 read=40520 written=68
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.012..958.347 rows=2000000 loops=1)
                     Buffers: shared hit=2 read=40520 written=68
 Planning time: 3.510 ms
 Execution time: 7362.543 ms
(19 rows)

COMMIT;
COMMIT