Kaminari should suffer from the same issues; it's still invoking count() on the scope (at least, it appears to, from the source), which is going to trigger the

Kaminari should suffer from the same issues; it's still invoking count() on the scope (at least, it appears to, from the source), which is going to trigger the problem. If you're counting the whole collection, it's going to be very fast, since mongo will just return the number of records in the collection, but if you're viewing a subset of the collection, it's still going to iterate over each record and do a value comparison.