How I solved an Ecto preload dilemma I had in Elixir (gatlin.io)

    There are a few issues to be aware of when using
    Repo.preload. First, it's hitting the database
    to fetch the association data.

FWIW, using Query.preload with will produce the same two queries when used with plain atoms like "Repo.all from p in Post, preload: [:comments]"