# File lib/thinking_sphinx/active_record.rb, line 189
      def add_sphinx_index(name, &block)
        index = ThinkingSphinx::Index::Builder.generate self, name, &block

        unless sphinx_indexes.any? { |i| i.name == index.name }
          add_sphinx_callbacks_and_extend(index.delta?)
          insert_sphinx_index index
        end
      end