begin
   for buff in (
      select username, db_link from user_db_links
       order by username, db_link )
   loop
      dbms_output.put_line('Running Tests for ' || buff.db_link);
      begin
        -- execute immediate 'begin wtplsql.test_all@' || buff.username ||
         execute immediate 'begin wtplsql.test_all@' || buff.db_link ||
                                            '; end;' ;
      exception when others
      then
         dbms_output.put_line(SQLERRM);
      end;
      commit;
   end loop;
end;