title: DyanamoDB SCAN with nested attribute
body: <p>Can I scan DynamoDB by 'order.shortCode', in the given example.  The console is indicating I can't with dot notation, and I can't find any documentation on it.</p>
  
  <pre><code>{    
    "key2": "cj11b1ygp0000jcgubpe5mso3",
    "order": {
      "amount": 74.22,
      "dateCreated": "2017-04-02T19:15:33-04:00",
      "orderNumber": "cj11b1ygp0000jcgubpe5mso3",
      "shortCode": "SJLLDE"
    },
    "skey2": "SJLLDE"
  }
  </code></pre>