title: How combine the sorted sets Redis?
body: <p>I use <code>sorted set</code> type in Redis store.
  For each user I create a own <strong>KEY</strong> and put here data:</p>
  
  <p>Example of <strong>KEY:</strong></p>
  
  <pre><code>FEED:USER:**1**, FEED:USER:**2**, FEED:USER:**3**
  </code></pre>
  
  <p>I want to select data from Redis for user's keys: 1, 2, 3 and sorted each by score (timestamp).</p>
  
  <p>If see at problem simply, I need select from any KEY a data across time and after combine all results sorted by score.</p>