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 '1993-04-01'
	and l_shipdate < cast(date '1993-04-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1163754.43..1163754.44 rows=1 width=29) (actual time=16772.977..16772.977 rows=1 loops=1)
   Buffers: shared hit=154961 read=295623 written=11184
   ->  Hash Join  (cost=101304.85..1150696.84 rows=746148 width=29) (actual time=3528.660..16106.051 rows=749017 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=154961 read=295623 written=11184
         ->  Bitmap Heap Scan on lineitem  (cost=15782.85..1048386.51 rows=746148 width=12) (actual time=740.627..10045.501 rows=749017 loops=1)
               Recheck Cond: ((l_shipdate >= '1993-04-01'::date) AND (l_shipdate < '1993-05-01'::date))
               Buffers: shared hit=154956 read=255103 written=11107
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15596.31 rows=746148 width=0) (actual time=529.271..529.271 rows=754251 loops=1)
                     Index Cond: ((l_shipdate >= '1993-04-01'::date) AND (l_shipdate < '1993-05-01'::date))
                     Buffers: shared read=2052
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2786.215..2786.215 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=2 read=40520 written=77
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.017..1556.606 rows=2000000 loops=1)
                     Buffers: shared hit=2 read=40520 written=77
 Total runtime: 16797.487 ms
(17 rows)

COMMIT;
COMMIT