title: ERROR: function dblink(unknown, unknown) does not exist
body: <p>I have defined a foreign server pointing to another database. I then want to execute a function in that database and get back the results.</p>
  
  <p>When I try this:</p>
  
  <pre><code>SELECT * FROM  dblink('mylink','select someschema.somefunction(''test'', ''ABC'')')
  </code></pre>
  
  <p>or this:</p>
  
  <pre><code>SELECT t.n FROM  dblink('mylink', 'select * from someschema.mytable') as t(n text)
  </code></pre>
  
  <p>I get the error:</p>
  
  <blockquote>
    <p>ERROR: function dblink(unknown, unknown) does not exist</p>
  </blockquote>
  
  <p>Running as superuser.</p>