title: Retrieving a subset of a JSON object stored in Dynamo
body: <p>Is it currently possible to retrieve a subset of a json object stored in Dynamo? For example, I have an attribute named record of JSON type which is an array of JSON objects:</p>
  
  <pre><code>records:
  [
      {"K1": "V1" },
      {"K2": "V2" },
      {"K3": "V3" },
      {"K4": "V4" }
  ]
  </code></pre>
  
  <p>I store them in the JSON format in Dynamo. I wanted to know if I can only retrieve key value pairs 1 to 2 and not the 3rd and 4th one? I am unsure if I can provide a specific filter expression to do this operation.</p>
  
  <p>If it is possible, I would love to hear the methodology as to how it can be done? </p>
  
  <p>Thanks! </p>