text: -- almost the whole db
    select m.id, m.model, m.version, a.id, u.first_fetch, u.last_fetch, u.description, u.price
      from maker_model m
      join ad a on a.model_id = m.id
      join ad_update u on a.id = u.ad_id
  order by m.model, m.version, a.id
  ;
  
  -- prices by model
    select m.model, count(a.id), min(u.price), avg(u.price), max(u.price)
      from maker_model m
      join ad a on a.model_id = m.id
      join ad_update u on a.id = u.ad_id
  group by m.model
  order by m.model
  ;
  