I’m trying to list some users with links to their posts (per specific topic), and have some basic pagination in place.

Users have many Posts preloaded like so:

query1 = from User, 
    offset: ^((page - 1) * per_page),
    limit: ^per_page    

query2 = from u in query1, 
      distinct: true,
      join: p in assoc(u, :posts),
      on: p.poster_id == u.id,
      where: p.topic_id in subquery(query_topic_ids())
      group_by: [u.id, p.id],
      preload: [posts: p]

Posts also belong to Topics (used here to load only relevant users)

Expected

When supplied a per_page: 1 as parameter the Repo.all(query2) should return 1 User with all associated Posts.

Actual

I get 1 User with only 1 associated post (although there are more posts).

So, how do I restrict the scope of the limit: operator to the parent schema (User) only?
How do I otherwise load and paginate only the users who posted under specific topic and also load such posts per user.

PS: Couldn’t find relevant info in the docs and on this forum or SO, and will appreciate any hints and pointers!