With statistics enabled TPCH 16 has two additional exchange operators

select
  p.p_brand,
  p.p_type,
  p.p_size,
  count(distinct ps.ps_suppkey) as supplier_cnt
from
  partsupp ps,
  part p
where
  p.p_partkey = ps.ps_partkey
  and p.p_brand <> 'Brand#21'
  and p.p_type not like 'MEDIUM PLATED%'
  and p.p_size in (38, 2, 8, 31, 44, 5, 14, 24)
  and ps.ps_suppkey not in (
    select
      s.s_suppkey
    from
      supplier s
    where
      s.s_comment like '%Customer%Complaints%'
  )
group by
  p.p_brand,
  p.p_type,
  p.p_size
order by
  supplier_cnt desc,
  p.p_brand,
  p.p_type,
  p.p_size;