title: Multiple redis calls or single call to Mongo or another DB engine
body: <p>I understand redis is fast and I find that I can implement many things using just redis. But at the expense of making multiple queries for example. In I use Mongo, I might have a model/schema like: </p>
  
  <p>Chatrooms (Mongo)</p>
  
  <ul>
  <li>_id: ObjectId</li>
  <li>name: string</li>
  <li>users: array</li>
  </ul>
  
  <p>With redis I need something abit more complex</p>
  
  <ul>
  <li><code>chatrooms:&lt;&lt;id&gt;&gt;</code> where id needs to be manually generated
  <ul>
  <li>name</li>
  </ul></li>
  <li><code>chatrooms:&lt;&lt;id&gt;&gt;:users</code> to store the set of users</li>
  </ul>
  
  <p>To retrieve chatroom details for mongo is straightforward, with mongo I need to incur 2 queries in this case. In a more complex use case, maybe more</p>
  
  <p>So I wonder from a performance point of view, which is more efficient? From a development point of view, definitely, its simpler to use Mongo for example. </p>