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 '1995-01-01'
	and l_shipdate < cast(date '1995-01-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1167749.19..1167749.21 rows=1 width=29) (actual time=7676.698..7676.698 rows=1 loops=1)
   Buffers: shared hit=230229 read=227858 dirtied=287 written=14670
   ->  Hash Join  (cost=101771.15..1154308.19 rows=768057 width=29) (actual time=2289.006..7300.544 rows=774975 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=230229 read=227858 dirtied=287 written=14670
         ->  Bitmap Heap Scan on lineitem  (cost=16249.15..1057265.34 rows=768057 width=12) (actual time=476.604..4398.877 rows=774975 loops=1)
               Recheck Cond: ((l_shipdate >= '1995-01-01'::date) AND (l_shipdate < '1995-02-01'::date))
               Heap Blocks: exact=415440
               Buffers: shared hit=226320 read=191242 dirtied=287 written=10243
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16057.14 rows=768057 width=0) (actual time=294.932..294.932 rows=779592 loops=1)
                     Index Cond: ((l_shipdate >= '1995-01-01'::date) AND (l_shipdate < '1995-02-01'::date))
                     Buffers: shared hit=362 read=1760 written=191
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1790.362..1790.362 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=3906 read=36616 written=4427
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.019..947.190 rows=2000000 loops=1)
                     Buffers: shared hit=3906 read=36616 written=4427
 Planning time: 2.662 ms
 Execution time: 7684.342 ms
(19 rows)

COMMIT;
COMMIT