Oracle Database Discussions

Hi!

I'm facing a strange situation with a user. I'm using Oracle 10g.

The first time I was creating a user y putted it in SYSTEM tablespace.
The user got SYSDBA privileges.

My problema is that I can log with this user in SQLPlus, but when I log
with with SYS as SYSDBA the user doesn't appear...
I want to delete this user but I don't know how.

Let me be more practical:

I open a command line:

1. sqlplus /nolog

SQL*Plus: Release 10.2.0.1.0 - Production on MiÚ Sep 3 11:08:47 2008

Copyright (c) 1982, 2005, Oracle. All rights reserved.

SQL>

2. SQL> connect oracle_des_usr/passwd@desora as sysdba

Conectado.

SQL>

3. SQL> SELECT username FROM dba_users;

USERNAME
------------------------------
DESA
MDDATA
DIP
SCOTT
TSMSYS
DBSNMP
SYSMAN
MDSYS
ORDSYS
CTXSYS
ANONYMOUS

USERNAME
------------------------------
EXFSYS
DMSYS
WMSYS
XDB
ORDPLUGINS
SI_INFORMTN_SCHEMA
OLAPSYS
MGMT_VIEW
SYS
SYSTEM
OUTLN

22 filas seleccionadas.

SQL>

Even further I try to alter the current user:

4. SQL> revoke dba from oracle_des_usr;

revoke dba from oracle_des_usr
*
ERROR en lÝnea 1:
ORA-01917: el usuario o rol 'ORACLE_DES_USR' no existe

And it doesn't know it...

Thanks in advance to any solution or any idea to solve this.