text: --Q4.3
  set schema 'ssb';
  select 
      d_year, s_city, p_brand,
      sum(lo_revenue - lo_supplycost) as profit
  from 
      dates, customer, supplier, part, lineorder
  where 
      lo_custkey = c_custkey
      and lo_suppkey = s_suppkey
      and lo_partkey = p_partkey
      and lo_orderdate = d_datekey
      and s_nation = 'UNITED STATES'
      and (d_year = 1997 or d_year = 1998)
      and p_category = 'MFGR#14'
  group by 
      d_year, s_city, p_brand
  order by 
      d_year, s_city, p_brand;
  