Use instead of to enable join reuse

app/controllers/statistics_controller.rb

@@ -78,7 +78,7 @@ class StatisticsController < ApplicationController
   end
 
   def statistics_last_login
-    @members = current_organization.members.active.joins(:user).
+    @members = current_organization.members.active.references(:user).
                order("users.current_sign_in_at ASC NULLS FIRST")
   end
 
@@ -88,7 +88,7 @@ class StatisticsController < ApplicationController
 
   def statistics_type_swaps
     offers = current_organization.posts.
-             where(type: "Offer").joins(:transfers, transfers: :movements).
+             where(type: "Offer").references(:transfers, transfers: :movements).
              select("posts.tags, posts.category_id, SUM(movements.amount) as
                      sum_of_transfers, COUNT(transfers.id) as
                      count_of_transfers").

app/models/post.rb

@@ -23,7 +23,7 @@ class Post < ActiveRecord::Base
   scope :by_organization, ->(org) { where(organization_id: org) if org }
 
   scope :with_member, -> {
-    joins(:organization, :user_members).
+    references(:organization, :user_members).
       where("members.organization_id = posts.organization_id").
       select("posts.*, members.member_uid as member_id")
   }

app/models/user.rb

@@ -19,7 +19,7 @@ class User < ActiveRecord::Base
 
   default_scope -> { order("users.id ASC") }
 
-  scope :actives, -> { joins(:members).where(members: { active: true }) }
+  scope :actives, -> { references(:members).where(members: { active: true }) }
   scope :online_active, -> { where("sign_in_count > 0") }
   scope :notifications, -> { where(notifications: true) }