I’ve worked through the book and it starts to click in my head. What’s missing for me are examples how to fallback to some lower level stuff like a custom ecto query with fragments. Sometimes some data needs to be fixed in bulk. It can’t be done in a single query, and the easiest way is to use ecto query in a recursive function that updates the data in smaller chunks in the background. It’s pretty simple using pure ecto, but I’m not sure how do do it using ash resources.