title: how to change postgresql password if my username contains period
body: <p>I want to change my pg/sql pwd using the syntax</p>
  
  <pre><code>alter user username WITH PASSWORD '*****';
  </code></pre>
  
  <p>The problem is that my user name contains a period, like <code>user.name</code>, and it seems the system doesn't allow a period in user name. </p>
  
  <p>So how can I change my password?</p>