title: How to select count as a percentage over the total in Oracle using any Oracle function?
body: <p>I have an SQL statement that counts over the total number of rows active packages whose end date is null.  I am currently doing this using <code>(x/y) * 100</code>:</p>
  
  <pre><code>SELECT (SELECT COUNT(*) 
            FROM packages 
           WHERE end_dt IS NULL) / (SELECT COUNT(*) 
                                      FROM packages) * 100 
    FROM DUAL;
  </code></pre>
  
  <p>I wonder if there is a way to make use of any Oracle function to express this more easily?</p>