title: SYSDBA Cannot Drop A User in Oracle 12.1.0.2
body: <p>Newbie in Oracle. I had successfully installed Oracle DB on CentOS 6.8. I have created two databases:</p>
  
  <ol>
  <li>orcl</li>
  <li>AVDB</li>
  </ol>
  
  <p>There are some users present in the 'AVDB' database. I wish to drop a user in the AVDB database. But I am getting insufficient privileges error even though I am connected as SYS AS SYSDBA user. I am even unable to create a user using sys user.</p>
  
  <p>However, when I am connected to the same database as a different user (the one I am trying to drop which is <code>avuser</code>) I am able to create users.</p>
  
  <pre><code>[oracle@via7was ~]$ sqlplus sys as sysdba
  
  SQL*Plus: Release 12.1.0.2.0 Production on Thu Feb 2 14:13:16 2017
  
  Copyright (c) 1982, 2014, Oracle.  All rights reserved.
  
  Enter password:
  
  Connected to:
  Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
  With the Partitioning, Oracle Label Security, OLAP, Advanced Analytics,
  Oracle Database Vault and Real Application Testing options
  
  SQL&gt; drop user avuser cascade;
  drop user avuser cascade
  *
  ERROR at line 1:
  ORA-01031: insufficient privileges
  
  SQL&gt; create user test1 identified by secret;
  create user test1 identified by secret
                                  *
  ERROR at line 1:
  ORA-01031: insufficient privileges
  
  SQL&gt; disconnect
  Disconnected from Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
  With the Partitioning, Oracle Label Security, OLAP, Advanced Analytics,
  Oracle Database Vault and Real Application Testing options
  SQL&gt; conn avuser
  Enter password:
  Connected.
  SQL&gt; create user test1 identified by secret;
  
  User created.
  </code></pre>