title: Use cases for hstore vs json datatypes in postgresql
body: <p>In Postgresql, the hstore and json datatypes seem to have very similar use cases. When would you choose to use one vs. the other? Initial thoughts:</p>
  
  <ul>
  <li>You can nest with json; you can't with hstore</li>
  <li>Functions for parsing json won't be available until 9.3</li>
  </ul>