# File lib/rubyrep/replication_extenders/postgresql_replication.rb, line 228
      def add_big_primary_key(table_name, key_name)
        old_message_level = select_one("show client_min_messages")['client_min_messages']
        execute "set client_min_messages = warning"
        execute("alter table \"\#{table_name}\" add column \#{key_name} bigserial\n")

        execute("alter table \"\#{table_name}\" add constraint \#{table_name}_\#{key_name}_pkey primary key (\#{key_name})\n")
        
      ensure
        execute "set client_min_messages = #{old_message_level}"
      end