title: django & AWS S3 - network/performance cost difference on enabling pre-signed url
body: <p>Say, I have a django project with static files stored on Amazon S3 with <code>django-storage</code> as a custom storage.</p>
  <p>Say, I have a static file called <code>style.css</code>.</p>
  <p>According to <a href="https://stackoverflow.com/questions/16777900/why-does-s3-using-with-boto-and-django-storages-give-signed-url-even-for-publi">this question</a>:</p>
  <ul>
  <li>By default, <code>AWS_QUERYSTRING_AUTH</code> is set to <code>True</code>, and the generated link will be as such : <code>https://bucket.s3.amazonaws.com/style.css?AWSAccessKeyId=xxxxxx&amp;Signature=xxxx&amp;Expires=1595823548</code></li>
  <li>But if I set <code>AWS_QUERYSTRING_AUTH</code> to <code>False</code>, the generated link will be as such : <code>https://bucket.s3.amazonaws.com/style.css</code> (e.g. without accessId, signature, and expire)</li>
  <li>for public file, they said I should set this to <code>False</code></li>
  </ul>
  <p>If I get this correctly, this is what people call a &quot;signed url&quot;.</p>
  <p>Functionality-wise, both of these 2 options above will work exaclty as the same, despite the longer link on the first option.</p>
  <p>My question are: performance-wise, does pre-signed url affect CPU/networking bandwith as much?</p>
  <p>If I have a hundreds of public files that can be served without pre-signed url, does my server get the overhead (in terms of CPU and networking) if I insist to serve all of it with presigned url ?</p>