title: Reactive - Combining Observable Interval with manual triggers
body: <p>I have <code>Observable.Interval(TimeSpan.FromSeconds(1))</code> and a subscriber that checks something in DB every time interval occurs. But sometimes when I do that check from DB i want to immediately perform another check(call that subscriber again because I know there is something in the queue).</p>
  
  <p>I have already managed to achieve something similar by combining Interval with <code>while</code> inside the subscriber method:</p>
  
  <pre><code> Observable              
  .Interval(TimeSpan.FromSeconds(1))
  .Sample(TimeSpan.FromSeconds(1)) //to avoid multiple 'stacked' intervals 
  .Subscribe(RepeatAction);
  
  
  private void RepeatAction(long _)
  {
      bool wasSuccess;
      do
      {
          wasSuccess = CheckingInDB(); //Long operation
      } while (wasSuccess );
  }
  </code></pre>
  
  <p>But is it possible to achieve that kind of behavior with <i>pure</i> reactive?</p>