serial?

# File activerecord/lib/active_record/connection_adapters/postgresql/column.rb, line 15
      def serial?
        return unless default_function

        if %{\Anextval\('"?(?<sequence_name>.+_(?<suffix>seq\d*))"?'::regclass\)\z} =~ default_function
          sequence_name_from_parts(table_name, name, suffix) == sequence_name
        end
      end