title: generating unique ids in hive
body: <p>I have been trying to generate unique ids for each row of a table (30 million+ rows).</p>
  
  <ul>
  <li>using sequential numbers obviously not does not work due to the parallel nature of Hadoop.</li>
  <li>the built in UDFs rand() and hash(rand(),unixtime()) seem to generate collisions.</li>
  </ul>
  
  <p>There has to be a simple way to generate row ids, and I was wondering of anyone has a solution.</p>
  
  <ul>
  <li>my next step is just creating a Java map reduce job to generate a real hash string with a secure random + host IP + current time as a seed. but I figure I'd ask here before doing it ;)</li>
  </ul>