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 '1996-01-01'
	and l_shipdate < cast(date '1996-01-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1181392.71..1181392.72 rows=1 width=29) (actual time=19848.950..19848.950 rows=1 loops=1)
   Buffers: shared hit=79845 read=374741 dirtied=45 written=13826
   ->  Hash Join  (cost=102343.36..1167518.15 rows=792832 width=29) (actual time=3936.841..19187.319 rows=771844 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=79845 read=374741 dirtied=45 written=13826
         ->  Bitmap Heap Scan on lineitem  (cost=16821.36..1064157.43 rows=792832 width=12) (actual time=1212.103..12642.265 rows=771844 loops=1)
               Recheck Cond: ((l_shipdate >= '1996-01-01'::date) AND (l_shipdate < '1996-02-01'::date))
               Buffers: shared hit=39324 read=374737 dirtied=45 written=13826
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16623.15 rows=792832 width=0) (actual time=935.200..935.200 rows=772620 loops=1)
                     Index Cond: ((l_shipdate >= '1996-01-01'::date) AND (l_shipdate < '1996-02-01'::date))
                     Buffers: shared hit=2 read=2112
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2722.940..2722.940 rows=2000000 loops=1)
               Buckets: 262144  Batches: 1  Memory Usage: 115519kB
               Buffers: shared hit=40518 read=4
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.020..931.071 rows=2000000 loops=1)
                     Buffers: shared hit=40518 read=4
 Total runtime: 19879.857 ms
(17 rows)

COMMIT;
COMMIT