title: Suggestion for Cassandra Data Model for Chat application
body: <p>I am currently developing a chat application on top of Cassandra. </p>
  
  <p>A <strong><em>conversation</em></strong> </p>
  
  <ul>
  <li>can happen between one or more users.</li>
  <li>can have more than one message.</li>
  <li>will be marked read if all the messages are read.</li>
  </ul>
  
  <p>In an extreme case, conversation can have upto 100 users.</p>
  
  <p>I want to solve the following query requirements.</p>
  
  <ul>
  <li>Show top n recent conversations for a given user. </li>
  <li>Show count of unread conversations (not messages) for a given user.</li>
  </ul>
  
  <p>Any suggestions on Data Modelling? </p>