Fix many N+1 queries

app/controllers/comments_controller.rb

@@ -4,7 +4,10 @@ class CommentsController < ApplicationController
   before_filter :set_subcreddit
 
   def show
-    @comments = @comment.subtree.arrange(order: :created_at)
+    @comments = @comment
+                  .subtree
+                  .includes(:post, :user)
+                  .arrange(order: :created_at)
   end
 
   def new

app/controllers/posts_controller.rb

@@ -3,11 +3,11 @@ class PostsController < ApplicationController
   before_filter :set_subcreddit
 
   def index
-    @posts = Post.all
+    @posts = Post.includes(:subcreddit, :user).all
   end
 
   def show
-    @comments = @post.comments.arrange(order: :created_at)
+    @comments = @post.comments.includes(:user).arrange(order: :created_at)
   end
 
   def new

app/controllers/users_controller.rb

@@ -1,7 +1,7 @@
 class UsersController < ApplicationController
   def show
     @user = User.friendly.find(params[:id])
-    @comments = @user.comments
+    @comments = @user.comments.includes(:post)
   end
 
   def new