title: Does DynamoDB expose an API to query or detect when there is conflict in merging item data
body: <p>DynamoDB is an AP system based on the original <a href="https://www.allthingsdistributed.com/2007/10/amazons_dynamo.html" rel="nofollow noreferrer">dynamo paper</a>.</p>
  <ul>
  <li>Is there any API to detect when a merge conflict has happened or resolved?</li>
  <li>Is there any API to provide a strategy to resolve a conflict if it happens.</li>
  </ul>