limit on eager loaded association ?

ActiveRecord can't currently do that, but it'd be a nice feature given how difficult it is to customize the eager loading queries.

However, you might be able emulate the functionality by constructing your own query to fetch the ids of the association that match. Then you could put them in a big array and pass them into the conditions on the final query.

There would be a lot of issues, and it might ultimately be slower than the n+1 queries. There's no direct way to limit the secondary results although you might be able to cook something up with subselects or other advanced db features.