Look for uses of present?, none?, any?, blank? and empty? on objects which may be ActiveRecord::Relations. Are you just going to load the entire array later if the relation is present? If so, add load to the call (e.g. @my_relation.load.any?) Be careful with your use of exists? - it ALWAYS executes a SQL query. Only use it in cases where that is appropriate - otherwise use present? or any other the other methods which use empty? Be extremely careful using where in instance methods on...