title: Firebase advanced queries
body: <p>I know it's a high discussed topic, but for me it's still not clear which is the best approach to create advanced queries in Firebase. </p>
  
  <p>Currently I'm using Angular 2 in the frontend and Firebase + NodeJS (Admin SDK) in the backend on an App engine. </p>
  
  <p>Frontend: Auth / Simple queries / writing non sensitive data</p>
  
  <p>NodeJS: Writing high sensitive data / validation </p>
  
  <p>Works perfectly fine!</p>
  
  <p>But now I want to create advanced queries and here's where I struggle:</p>
  
  <ul>
  <li>Firebase's built in query's are not powerful enough</li>
  <li>Client side would be too bad for performance reasons.</li>
  <li>Same for server side. I would need to transfer all the unqueried data anyways to my server.</li>
  </ul>
  
  <p>So is there any good approach to avoid transfer unqueried data? Maybe since I'm using the gcloud anyways for the admin sdk? </p>
  
  <p>I really miss something like custom endpoints.</p>
  
  <p>THX in advance!</p>