title: How to make a lookup-table in cassandra
body: <p>I want to create a table in <em>cassandra</em>, that is used as a lookup table. I have a lot of urls in my database and want to store ids instead of the urls-strings. So my approach is, to store the urls in a table with two columns: <code>id</code> (int) and <code>url</code> (text).</p>
  
  <p>My problem is, that I need an index for the <em>url</em> field and also for the id field. </p>
  
  <p>The <em>first index</em> is used during progressing new ulrs (so find an <code>id</code> for an url in the database) and the <em>second index</em> is use during displaying data (get the <code>url</code> for an id).</p>
  
  <p>How can I implement that in <em>cassandra</em>?</p>