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 '1994-04-01'
	and l_shipdate < cast(date '1994-04-01' + interval '1 month' as date);
                                                                                QUERY PLAN                                                                                 
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1153210.59..1153210.60 rows=1 width=29) (actual time=7486.605..7486.605 rows=1 loops=1)
   Buffers: shared hit=212890 read=234928 dirtied=133 written=494
   ->  Hash Join  (cost=101275.54..1140205.99 rows=743120 width=29) (actual time=2881.119..7129.371 rows=747539 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=212890 read=234928 dirtied=133 written=494
         ->  Bitmap Heap Scan on lineitem  (cost=15753.55..1043537.19 rows=743120 width=12) (actual time=1347.498..4843.715 rows=747539 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-04-01'::date) AND (l_shipdate < '1994-05-01'::date))
               Heap Blocks: exact=405248
               Buffers: shared hit=210955 read=196338 dirtied=133 written=494
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15567.77 rows=743120 width=0) (actual time=1184.328..1184.328 rows=748346 loops=1)
                     Index Cond: ((l_shipdate >= '1994-04-01'::date) AND (l_shipdate < '1994-05-01'::date))
                     Buffers: shared hit=3 read=2042
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1523.163..1523.163 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=1932 read=38590
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.022..855.918 rows=2000000 loops=1)
                     Buffers: shared hit=1932 read=38590
 Planning time: 2.173 ms
 Execution time: 7491.443 ms
(19 rows)

COMMIT;
COMMIT