The middle ground to this sounds like a skip-list, but I haven't seen that implemented inside a SQL system. Maybe a trigger on inserts to the count row to rand

The middle ground to this sounds like a skip-list, but I haven't seen that implemented inside a SQL system. Maybe a trigger on inserts to the count row to randomly insert the skip list count. Problem would be, this would essentially require ordering and a transaction, so maybe could be calculated offline in an async way in some way.