title: In Firebase, how can I query the most recent 10 child nodes?
body: <p>I'm using <code>childByAutoId()</code> to generate my children. Each child looks like:</p>
  
  <pre><code>{
      user_id: 1
  }
  </code></pre>
  
  <p>I'd like to get the last 10 most recently added, sorted by time DESC. What's the easiest way to do this?</p>