title: SQL Error: ORA-12712: new character set must be a superset of old character set
body: <p>I want to change character set of oracle database from 'WE8MSWIN1252' to 'AL32UTF8'</p>
  
  <p>I tried to execute following steps from the link (http://download.oracle.com/docs/cd/B10501_01/server.920/a96529/ch10.htm#1009580):</p>
  
  <blockquote>
    <p>Shut down the database, using either a SHUTDOWN IMMEDIATE or a
    SHUTDOWN NORMAL statement. Do a full backup of the database because
    the ALTER DATABASE CHARACTER SET statement cannot be rolled back.
    Complete the following statements:</p>
  </blockquote>
  
  <pre><code>STARTUP MOUNT;
  ALTER SYSTEM ENABLE RESTRICTED SESSION;
  ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;
  ALTER SYSTEM SET AQ_TM_PROCESSES=0;
  ALTER DATABASE OPEN;
  ALTER DATABASE CHARACTER SET AL32UTF8;
  </code></pre>
  
  <p>But when i execute the above statement, I am getting the following error</p>
  
  <p>SQL Error: ORA-12712: new character set must be a superset of old character set</p>
  
  <p>Can anyone please help me in resolving this issue.</p>