If you want something a bit more specific to full DB language translations instead of just gettext style things (which you can do with a simple DB lookup and maybe a cache) then trans might be what you want as well.

No, AFAIK it is not possible. What you can achieve though is that you can provide your own helper that will localise the field from the DB, for example you if you store text in PostgreSQL and you use hstore plugin to localise fields then you can do:

def localise_db(field) do
  field[Gettext.get_locale()]
end

And then in your views use localise_db article.title.

Postgres can certainly select only parts of json fields. I’m not sure if Trans uses it though.