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 '1996-07-01'
	and l_shipdate < cast(date '1996-07-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1174551.91..1174551.92 rows=1 width=29) (actual time=7759.271..7759.271 rows=1 loops=1)
   Buffers: shared hit=172788 read=284872 written=162
   ->  Hash Join  (cost=101950.99..1160940.44 rows=777798 width=29) (actual time=2191.676..7362.827 rows=772743 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=172788 read=284872 written=162
         ->  Bitmap Heap Scan on lineitem  (cost=16428.99..1063751.47 rows=777798 width=12) (actual time=507.817..4944.695 rows=772743 loops=1)
               Recheck Cond: ((l_shipdate >= '1996-07-01'::date) AND (l_shipdate < '1996-08-01'::date))
               Heap Blocks: exact=415023
               Buffers: shared hit=171369 read=245766 written=136
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16234.55 rows=777798 width=0) (actual time=346.292..346.292 rows=778784 loops=1)
                     Index Cond: ((l_shipdate >= '1996-07-01'::date) AND (l_shipdate < '1996-08-01'::date))
                     Buffers: shared read=2112
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1672.349..1672.349 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=1416 read=39106 written=26
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.010..985.298 rows=2000000 loops=1)
                     Buffers: shared hit=1416 read=39106 written=26
 Planning time: 3.579 ms
 Execution time: 7762.649 ms
(19 rows)

COMMIT;
COMMIT