title: postgresql – No crypt function on Debian stretch
body: <p>I have PostgreSQL 9.6 installation on my Debian Stretch (9). When I want to use <code>crypt()</code> or <code>gen_salt()</code> functions, it says:</p>
  
  <pre><code>ERROR:  function gen_salt(unknown, integer) does not exist
  LINE 1: select gen_salt('bf', 8)
                 ^
  HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
  </code></pre>
  
  <p>How can I get these functions working?</p>
  
  <hr>
  
  <p><a href="https://pastebin.com/YEjgWkBF" rel="nofollow noreferrer">Installed postgresql packages</a></p>