title: How do I restrict access to sys_context in Oracle?
body: <p>I would like to be able to prevent a readonly database user from being able to access some system functions, such as sys_context. i.e.</p>
  
  <pre><code>SELECT sys_context('USERENV', 'SID') FROM DUAL;
  SELECT SYS.DATABASE_NAME FROM dual;
  SELECT dbms_utility.port_string FROM dual;
  </code></pre>
  
  <p>*Edit: With the responses provided here and additional things tried on my side, a lengthy report was provided to biz. They decided that attempting to restrict these rights were not worth the risk and thus it was dropped.</p>