title: Composite key / secondary indexing strategy in Redis
body: <p>Say I have some data of the following sort that I want to store in Redis:</p>
  
  <pre><code>* UUID
  * State (e.g. PROCESSED, WAITING_FOR_RESPONSE)
  * […] other vals
  </code></pre>
  
  <p>The <code>UUID</code> or the <code>State</code> are the only two variables that I will ever need to query on</p>
  
  <ul>
  <li>What data structure in Redis is most suited for this?</li>
  <li>How would I go about structuring the keys?</li>
  </ul>