PERF: only rebuild entire top topic table daily

app/jobs/scheduled/daily.rb

@@ -0,0 +1,19 @@
+require_dependency 'score_calculator'
+
+module Jobs
+
+  # This job will run on a regular basis to update statistics and denormalized data.
+  # If it does not run, the site will not function properly.
+  class PeriodicalUpdates < Jobs::Scheduled
+    every 1.day
+
+    def execute(args)
+      # TODO: optimise this against a big site before doing this any more
+      # frequently
+      #
+      # current implementation wipes an entire table and rebuilds causing huge
+      # amounts of IO
+      TopTopic.refresh!
+    end
+  end
+end

app/jobs/scheduled/periodical_updates.rb

@@ -21,8 +21,6 @@ module Jobs
       # Update the scores of posts
       ScoreCalculator.new.calculate
 
-      # Refresh Top Topics
-      TopTopic.refresh!
 
       # Automatically close stuff that we missed
       Topic.auto_close