From a2571ba9b982e1a02380db89bef07e274a9ad01c Mon Sep 17 00:00:00 2001
From: Antonio Terceiro <terceiro@colivre.coop.br>
Date: Fri, 15 Oct 2010 14:27:16 -0300
Subject: [PATCH] Fix migration to run at a reasonable time

---
 db/migrate/20100928000952_aggressive_indexing_strategy2.rb | 30 +++++++++++++++++++++++++++++-
 db/schema.rb                                               |  6 +++++-
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/db/migrate/20100928000952_aggressive_indexing_strategy2.rb b/db/migrate/20100928000952_aggressive_indexing_strategy2.rb
index 40c8aa6..bb7adc4 100644
--- a/db/migrate/20100928000952_aggressive_indexing_strategy2.rb
+++ b/db/migrate/20100928000952_aggressive_indexing_strategy2.rb
@@ -1,6 +1,34 @@
 class AggressiveIndexingStrategy2 < ActiveRecord::Migration
   def self.up
-    execute("delete from action_tracker_notifications where id not in (select distinct(atn.id) from action_tracker_notifications as atn JOIN action_tracker_notifications as t ON  (t.profile_id = atn.profile_id and t.action_tracker_id = atn.action_tracker_id and atn.id < t.id))")
+
+    say 'Removing duplicate notification records ...'
+    buffer = ''
+    removed = 0
+    select_all(
+      'select min(id) as min_id, action_tracker_id, profile_id, count(*)
+      from action_tracker_notifications
+      group by action_tracker_id, profile_id
+      having count(*) > 1'
+    ).each do |duplicate|
+      buffer += ('delete from action_tracker_notifications
+        where
+          profile_id = %d AND
+          action_tracker_id = %s AND
+        id > %d;
+        ' % [duplicate['profile_id'], duplicate['action_tracker_id'], duplicate['min_id']]
+      )
+      if removed % 100 == 0
+        execute buffer
+        say "Deleted " + removed.to_s
+        buffer = ''
+      end
+      removed += 1
+    end
+
+    if !buffer.empty?
+      execute buffer
+    end
+
     add_index(:action_tracker_notifications, :profile_id)
     add_index(:action_tracker_notifications, :action_tracker_id)
     add_index(:action_tracker_notifications, [:profile_id, :action_tracker_id], :unique => true)
diff --git a/db/schema.rb b/db/schema.rb
index 39fbe4d..ee2bebd 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -9,7 +9,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20100923160040) do
+ActiveRecord::Schema.define(:version => 20100928000952) do
 
   create_table "action_tracker", :force => true do |t|
     t.integer  "user_id"
@@ -31,6 +31,10 @@ ActiveRecord::Schema.define(:version => 20100923160040) do
     t.integer "profile_id"
   end
 
+  add_index "action_tracker_notifications", ["action_tracker_id"], :name => "index_action_tracker_notifications_on_action_tracker_id"
+  add_index "action_tracker_notifications", ["profile_id", "action_tracker_id"], :name => "index_action_tracker_notifications_on_profile_id_and_action_tracker_id", :unique => true
+  add_index "action_tracker_notifications", ["profile_id"], :name => "index_action_tracker_notifications_on_profile_id"
+
   create_table "article_versions", :force => true do |t|
     t.integer  "article_id"
     t.integer  "version"
--
libgit2 0.21.2