text: --Q2.1
  set schema 'ssb';
  select 
      sum(lo_revenue), d_year, p_brand
  from 
      lineorder, dates, part, supplier
  where 
      lo_orderdate = d_datekey
      and lo_partkey = p_partkey
      and lo_suppkey = s_suppkey
      and p_category = 'MFGR#12'
      and s_region = 'AMERICA'
  group by 
      d_year, p_brand
  order by 
      d_year, p_brand;
  