title: Issue with Invalid User logging in PostgreSQL
body: <p>When I write <code>createdb mydb</code> in the bash terminal. I write the password, but I am getting an error for a user &quot;amodhakal&quot;. I have not set up that user, so I was wondering how I can change that user to &quot;postgres&quot; so I can use <code>createdb mydb</code>. Thank You for helping. If more clarification is needed, just let me know!</p>
  <pre><code>$ createdb mydb
  Password: 
  Password: 
  createdb: error: connection to server at &quot;localhost&quot; (::1), port 5432 failed: FATAL:  password authentication failed for user &quot;amodhakal&quot;
  </code></pre>
  <p>When I type psql, I get password for user amodhakal. Like I said, that user doesn't exist so I need to delete that user, and change it to &quot;postgres&quot;</p>
  <pre><code>psql
  Password for user amodhakal:
  </code></pre>