加载时检测到 Rails eager loading

问：

我在加载页面时遇到这些错误。

USE eager loading detected
  Notification => [:actor]
  Add to your query: .includes([:actor])
Call stack
  .../views/api/notifications/index.json.jbuilder:6

USE eager loading detected
  Notification => [:notifiable]
  Add to your query: .includes([:notifiable])
Call stack
  .../views/api/notifications/index.json.jbuilder:9

在我看来，/views/api/notifications/index.json.jbuilder

json.new_notification_count @new_notification_count
json.next_page @notifications.next_page
json.notifications do |json|
  json.array! @notifications do |notification|
    json.id notification.id
    json.actor notification.actor.username
    json.actor_avatar_img_tag avatar_of(notification.actor, size: 40)
    json.action notification.action
    json.type notification.notifiable.class.to_s.underscore.humanize.downcase
    json.url case notification.notifiable.class.to_s
              when "Post" then post_path(notification.notifiable)
              when "User" then user_path(notification.notifiable)
              when "Response" then post_path(notification.notifiable.post, anchor: "response_#{notification.notifiable.id}")
              when "Message" then conversations_path(notification.notifiable)
              when "Order" then order_path(notification.notifiable)
             end
    json.time_ago time_ago_in_words(notification.created_at) + " ago"
    json.unread notification.read_at.nil?
  end
end

在我的控制器中

def index
    @notifications = Notification.where(recipient: current_user)
                                 .recent.paginate(page: params[:page], per_page: 8)
    @new_notification_count = Notification.where(recipient: current_user, is_new: true).count
end

在我的模型中

belongs_to :recipient, class_name: "User"
belongs_to :actor, class_name: "User"
belongs_to :notifiable, polymorphic: true

scope :pristine, -> { where(is_new: true) }
scope :recent, -> { order(created_at: :desc) }
scope :unread, -> { where(read_at: nil) }

这是一个示例脚本。

      Notification.create(recipient: receiver, 
                          actor: current_user, 
                          action: "sent you the ", 
                          notifiable: @message, 
                          is_new: true
                         )

我的项目上没有 Bullet gem。谁能建议我如何解决这个问题？