fix #936 by adding index on state for todos. Needs migration of database.

db/migrate/20100502162317_add_index_to_todo_state.rb

@@ -0,0 +1,9 @@
+class AddIndexToTodoState < ActiveRecord::Migration
+  def self.up
+    add_index :todos, :state
+  end
+
+  def self.down
+    remove_index :todos, :state
+  end
+end