Performance improvement on workflow setup screen.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@957 e93f8b46-1217-0410-a6f0-8f06a7374b81

db/migrate/085_add_role_tracker_old_status_index_to_workflows.rb

@@ -0,0 +1,9 @@
+class AddRoleTrackerOldStatusIndexToWorkflows < ActiveRecord::Migration
+  def self.up
+    add_index :workflows, [:role_id, :tracker_id, :old_status_id], :name => :workflows_role_tracker_old_status
+  end
+
+  def self.down
+    remove_index :workflows, :name => :workflows_role_tracker_old_status
+  end
+end