More efficient hot questions selection

app/controllers/application_controller.rb

@@ -105,9 +105,9 @@ class ApplicationController < ActionController::Base
   end
 
   def pull_hot_questions
-    @hot_questions = Rails.cache.fetch('hot_questions', expires_in: 30.minutes) do
-      Post.undeleted.where(updated_at: (Rails.env.development? ? 365 : 1).days.ago..Time.now)
-          .where(parent_id: nil).includes(:category)
+    @hot_questions = Rails.cache.fetch('hot_questions', expires_in: 4.hours) do
+      Post.undeleted.where(updated_at: (Rails.env.development? ? 365 : 7).days.ago..Time.now)
+          .where(post_type_id: Question.post_type_id).includes(:category)
           .order('score DESC').limit(SiteSetting['HotQuestionsCount'])
     end
   end

app/views/layouts/_sidebar.html.erb

@@ -12,7 +12,7 @@
     <% end %>
   <% end %>
 
-  <% if Rails.env.development? || @hot_questions.size > 0 %>
+  <% if Rails.env.development? || @hot_questions.to_a.size > 0 %>
     <div class="widget has-margin-4">
       <h4 class="widget--header has-margin-0">Hot Posts</h4>
       <% @hot_questions.each do |hq| %>