From 01075c5e7ac0c0edf96cdcad462d509699f0d455 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9gis=20Hanol?= <regis@hanol.fr>
Date: Tue, 1 Oct 2013 17:11:13 +0200
Subject: [PATCH] =?UTF-8?q?FIX=20database=20growth=20when=20running=20the?=
 =?UTF-8?q?=20=EF=BB=BFPeriodicalUpdates=20job?=
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---
 lib/score_calculator.rb | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/lib/score_calculator.rb b/lib/score_calculator.rb
index 489f6907918..8efedd91827 100644
--- a/lib/score_calculator.rb
+++ b/lib/score_calculator.rb
@@ -22,7 +22,6 @@ class ScoreCalculator
     exec_sql(post_score_sql, @weightings)
 
     # Update the percent rankings of the posts
-
     exec_sql("UPDATE posts SET percent_rank = x.percent_rank
               FROM (SELECT id, percent_rank()
                     OVER (PARTITION BY topic_id ORDER BY SCORE DESC) as percent_rank
@@ -73,12 +72,12 @@ class ScoreCalculator
 
     # Generate a SQL statement to update the scores of all posts
     def post_score_sql
-      "UPDATE posts SET score = ".tap do |sql|
-        components = []
-        @weightings.keys.each do |k|
-          components << "COALESCE(#{k.to_s}, 0) * :#{k.to_s}"
-        end
-        sql << components.join(" + ")
-      end
+      components = []
+      @weightings.keys.each { |k| components << "COALESCE(#{k.to_s}, 0) * :#{k.to_s}" }
+      components = components.join(" + ")
+
+      "UPDATE posts SET score = x.score
+       FROM (SELECT id, #{components} as score FROM posts) AS x
+       WHERE x.id = posts.id AND (posts.score IS NULL OR x.score <> posts.score)"
     end
 end