title: cassandra, select via a non primary key
body: <p>I'm new with cassandra and I met a problem. I created a keyspace demodb and a table users. This table got 3 columns: id (int and primary key), firstname (varchar), name (varchar).
  this request send me the good result:</p>
  
  <pre><code>SELECT * FROM demodb.users WHERE id = 3;
  </code></pre>
  
  <p>but this one:</p>
  
  <pre><code>SELECT * FROM demodb.users WHERE firstname = 'francois';
  </code></pre>
  
  <p>doesn't work and I get the following error message:</p>
  
  <pre><code>InvalidRequest: code=2200 [Invalid query] message="No secondary indexes on the restricted columns support the provided operators: "
  </code></pre>
  
  <p>This request also doesn't work:</p>
  
  <pre><code>SELECT * FROM users WHERE firstname  = 'francois'  ORDER BY id DESC LIMIT 5;
  InvalidRequest: code=2200 [Invalid query] message="ORDER BY with 2ndary indexes is not supported."
  </code></pre>
  
  <p>Thanks in advance.</p>