title: How to check connected user on psql
body: <p>In my PostgreSQL database I have 2 users: postgres and myuser.</p>
  
  <p>The default user is postgres, but this user has no permission to query my foreign tables and myuser does. How can I check if I'm connected with the right user?</p>
  
  <p>If I'm using the wrong user, how do I change to the right one?</p>