fix pool version ordering

db/migrate/20130221214811_add_index_updated_at_on_pool_versions.rb

@@ -0,0 +1,11 @@
+class AddIndexUpdatedAtOnPoolVersions < ActiveRecord::Migration
+  def up
+    execute "set statement_timeout = 0"
+    add_index :post_versions, :updated_at
+  end
+
+  def down
+    execute "set statement_timeout = 0"
+    remove_index :post_versions, :updated_at
+  end
+end