title: 'Integer' type or 'String' type Ids for entities in the database/application?
body: <p>I am building an application in Java. My database (<a href="http://en.wikipedia.org/wiki/Apache_Cassandra" rel="nofollow">Cassandra</a>) understands only <code>byte[]</code> as data. Thus I am free to choose among the several datatypes, for various entities IDs like the userIds or contentIds. </p>
  
  <p>What should be the preferred datatype for allocating these IDs. I am looking towards sequential integeral values as userIds for the users on the application. By the database design (as planned out), a single user is going to have 4 rows in the DB. To distinguish between these four rows, I could perhaps add an extra digit to userId towards the right most digit, that will help me in distinguishing among the 4 rows.</p>
  
  <p>Does this look like a good solution? Or would String Ids be preferred ?</p>
  
  <p>Any feedback is appreciated..</p>