def purge_by_remaining(remaining, window = nil, &block)
      _log.info("Purging #{table_name.humanize} older than last #{remaining} results...")
      total = purge_in_batches(purge_ids_for_remaining(remaining), window || purge_window_size, &block)
      _log.info("Purging #{table_name.humanize} older than last #{remaining} results...Complete - Deleted #{total} records")
      total