PERF: hit all index conditions to speed up anon ip tracking

app/models/topic_view_item.rb

@@ -33,7 +33,7 @@ class TopicViewItem < ActiveRecord::Base
         builder = SqlBuilder.new(sql)
 
         if !user_id
-          builder.where("ip_address = :ip_address AND topic_id = :topic_id")
+          builder.where("ip_address = :ip_address AND topic_id = :topic_id AND user_id IS NULL")
         else
           builder.where("user_id = :user_id AND topic_id = :topic_id")
         end

app/serializers/topic_view_serializer.rb

@@ -124,6 +124,7 @@ class TopicViewSerializer < ApplicationSerializer
   def include_is_warning?
     is_warning
   end
+
   def draft
     object.draft
   end