Added an index on custom_values table (customized_type + customized_id columns) to speed up issue queries that use custom field filters.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@702 e93f8b46-1217-0410-a6f0-8f06a7374b81

db/migrate/066_add_custom_value_customized_index.rb

@@ -0,0 +1,9 @@
+class AddCustomValueCustomizedIndex < ActiveRecord::Migration
+  def self.up
+    add_index :custom_values, [:customized_type, :customized_id], :name => :custom_values_customized
+  end
+
+  def self.down
+    remove_index :custom_values, :name => :custom_values_customized
+  end
+end