@spec build_page(Ecto.Queryable.t(), integer() | nil, integer() | nil, atom()) ::
  t(any())

Returns a Page struct for a query.

field is use to define the field that will be used for the count aggregate, which should be the same as the field used for order_by See https://stackoverflow.com/q/12693089/10204399

@spec chunk(Ecto.Queryable.t(), integer()) :: Stream.t()

Stream chunks of results from the given queryable.

Unlike Repo.stream, this function does not keep a long running transaction open. Hence, consistency is not guarenteed in the presence of rows being deleted or sort criteria changing.

Example

Ecto.Query.from(u in Users, order_by: [asc: :created_at]) |> Repo.chunk(100) |> Stream.map(&process_batch_of_users) |> Stream.run()

Source

https://elixirforum.com/t/what-is-the-best-approach-for-fetching-large-amount-of-records-from-postgresql-with-ecto/3766/8

@spec paginate(Ecto.Queryable.t() | struct(), integer() | nil, integer() | nil) ::
  Ecto.Query.t()

Add limit and offset to the query.