Hi,

You can get ” ORA-12631: Username retrieval failed ” error when login Oracle database.

ORA-12631: Username retrieval failed

When I login Oracle database via sqlplus on Windows server, I got following error.

PS C:\Users\Mehmet> sqlplus / as sysdba

SQL*Plus: Release 12.1.0.2.0 Production on Thu Jul 4 12:03:41 2019

Copyright (c) 1982, 2010, Oracle. All rights reserved.

ERROR:
ORA-12631: Username retrieval failed


Enter user-name: PS C:\Users\Mehmet>
PS C:\Users\Mehmet>

To solve this problem, change SQLNET.AUTHENTICATION_SERVICES= (NTS) parameter to SQLNET.AUTHENTICATION_SERVICES = (NONE) on sqlnet.ora under $ORACLE_HOME/NETWORK/ADMIN directory.

After changing this parameter, check again it will be solved.

PS C:\Users\Mehmet>
PS C:\Users\Mehmet> sqlplus / as sysdba

SQL*Plus: Release 12.1.0.2.0 Production on Thu Jul 4 12:06:54 2019

Copyright (c) 1982, 2010, Oracle. All rights reserved.


Connected to:
Oracle Database 12c Release 12.1.0.2.0 - 64bit Production

SQL>

Do you want to learn Oracle Database for Beginners, then read the following articles.

Oracle Tutorial | Oracle Database Tutorials for Beginners ( Junior Oracle DBA )