title: Overlapping Models in Myrrix
body: <p>I'm currently using Myrrix to get recommendations as follows:</p>
  
  <pre><code>User,Item,Score
  </code></pre>
  
  <p>But I'd like to add the ability to recommend as follows:</p>
  
  <pre><code>Collection,Item,1
  </code></pre>
  
  <p>(where <code>Collection</code> is a group of <code>Item</code>s - I could have called this Album and Song, but yes, the actual use case does make sense...)</p>
  
  <p>Now, the answer at <a href="https://stackoverflow.com/q/16721216/954442">Multiple models in Myrrix</a> suggests I should split across multiple Myrrix instances, which I'd rather not do if possible (memory overhead is a slight concern).</p>
  
  <p>It just so happens that <code>Collection</code> Ids are guaranteed to be in the top half of the long range, and <code>User</code> Ids in the bottom half, i.e. they cannot overlap. Does that mean that as long as I use the rescorer to keep the two types apart, I can keep everything together without the two sets of recommendations overlapping?</p>
  
  <p>Or if this a fool's errand, would it be more efficient to just go for the two Myrrix approach?</p>