title: Does Azure Cosmos DB not support MongoDB/Mongoose unique index?
body: <p>Using a unique constraint in Mongoose like:</p>
  
  <pre><code>email: { type:String, unique:true }
  </code></pre>
  
  <p>doesn't seem to work.  I can save several users with the same email.</p>
  
  <p>Is there something I need to do to create a unique index?</p>