title: How long will the PostgreSQL user password expire when the valuntil value in pq_user is NULL?
body: <p>Today, a magic happen to our read-only user in our PostgreSQL database. We can't log in to the database using provided username and password. It supposed to be someone changed the password, but no one. When I check the following query:</p>
  
  <pre><code>SELECT * FROM pg_user WHERE usename='readonlyuser';
  </code></pre>
  
  <p>I know the fact that valuntil value is totally different between the read-only user and normal user. valuntil value for the normal user is infinity, and NULL for the read-only user. And my question is: How long will the PostgreSQL user password expire when the valuntil value in pq_user is NULL?</p>