begin	
  -- Initialize the block
  go_block('emp');
  execute_query;
  first_record;

  -- An infinite loop through all rows in the block
  loop
    if :system.last_record = 'TRUE' then
       first_record;
    else
       next_record;
       dbms_lock.sleep(1);    -- pause a second
    end if;
    synchronize;              -- without it, you won't see anything happen
  end loop;
end;

DECLARE

  v_timer TIMER;
  
BEGIN  
  -- Initialize the block
  go_block('do_sample');
  execute_query;
  first_record;
  v_timer := Create_Timer('MYTIMER', 1000, REPEAT); --runs every second, change as appropriate

END;

DECLARE

  v_timer TIMER;
  
BEGIN
  
  v_timer := Find_Timer('MYTIMER');
  
  If NOT ID_NULL(v_timer) THEN
    
    IF :system.last_record = 'TRUE' THEN
      
      first_record;
      
    ELSE
      
      next_record;
      
    END IF;
    
    synchronize; -- without it, you won't see anything happen
    
  END IF;
  
END;