title: Cassandra Update - Some clustering keys are missing (timestamp)
body: <p>I have a Cassandra table that looks like:</p>
  
  <pre><code>CREATE TABLE messages (
      user_id INT, 
      message_id INT,
      received_timestamp TIMESTAMP, 
      status TEXT,
      message TEXT, 
      PRIMARY KEY ((user_id, message_id),received_timestamp)) 
      WITH CLUSTERING ORDER BY (received_timestamp DESC);
  </code></pre>
  
  <p>If I try to update a row such as:</p>
  
  <pre><code>UPDATE messages SET status = 'success' WHERE user_id = 1 AND message_id = 1;
  </code></pre>
  
  <p>I get an error:</p>
  
  <pre><code>Some clustering keys are missing: received_timestamp
  </code></pre>
  
  <p>I understand that I need to include the received_timestamp because it's part of the primary key, however I'm only including it in the primary key for ordering purposes.  Is there no way to perform an update here if I don't know the received_timestamp value?  If not, is there a better way to create this table that might work for this use case?  Thanks in advance.</p>