Best practice for use preload

best_binding_example.ex

def list_user_posts(user_id) do
  Post
  |> where([p], p.user_id == ^user_id)
  |> join(
      :inner,
      [post],
      user in User,
      on: user.id == post.user_id and is_nil(user.deleted_at) == true and
        is_nil(user.blocked_at) == true
    )
  |> preload([p, u], user: u) # generate one query
  |> preload(user: [:country, :city]) # generate 2 parallel preload query
end