title: DynamoDB + Store Values as Items or JSON
body: <p>New to DynamoDB.</p>
  
  <p>I'm creating a table with Primary Key 'UserID', Composite Key 'DateTime' and then I have the following as a value (note: I don't need to query any specifics in the below data - just write and read it):</p>
  
  <pre><code>UserID1
  UserID2
  Message
  DateTime
  </code></pre>
  
  <p>Questions: </p>
  
  <ol>
  <li>is there any advantage in storing these 4 values as separate items or as one JSON string?</li>
  <li>UserID1 and Datetime in the stored value also make up the Primary/Composite Key - am I right assuming there is no point in storing these in the data/value as I can access this from the returned Keys when quering?</li>
  </ol>