How do you connect to an oracle database with os authentication linux

Let’s say we want to create a database user who logs in with their OS account. To do so, we will use the “external authentication” option offered by oracle.

Check the value of the os_authent_prefix parameter

SQL> show parameter os_authent_prefix

NAME                                 TYPE        VALUE

------------------------------------ ----------- ------------------------------

os_authent_prefix                    string      ops$

The ops$ value is the prefix that oracle will use for each OS account. As we can see, our user is prefixed with ops$. Oracle uses the prefix to recognize OS users when they attempt to connect. It is also a way for Oracle to separate a database account and an OS account.


Let’s create the external user account in the database

SQL> create user ops$mikando identified externally;

As we can see, our user is prefixed with ops$.


Give the necessary privileges

SQL> grant connect, resource, create session to ops$mikando;


Let’s create the user named mikando and his password.

[[email protected] ~]# useradd -g oinstall -G dba,oper,asmdba mikando
[[email protected] ~]# passwd mikando


Open a new session and connect with the new operating system (os) user created “mikando”

login as: mikando

[email protected]'s password


Load the  database

[[email protected] ~]$  . oraenvoracle database 11

ORACLE_SID = [mikando] ? achats

ORACLE_BASE environment variable is not being set since this

information is not available for the current user ID mikando.

You can set ORACLE_BASE manually if it is required.

Resetting ORACLE_BASE to its previous value or ORACLE_HOME

The Oracle base has been set to /u01/app/oracle/product/12.1.0/db

Here, our target database is called achats


Connect to database

[[email protected] ~]$ sqlplus /

SQL*Plus: Release Production on Mon Dec 23 09:47:48 2019

Copyright (c) 1982, 2014, Oracle.  All rights reserved.

Connected to:

Oracle Database 12c Enterprise Edition Release - 64bit Production

With the Partitioning, Automatic Storage Management, OLAP, Advanced Analytics

and Real Application Testing options



Now the os user named “mikando” can connect to the database without being asked for a password.

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An IT professional with more than 4 years of experience as an Oracle database administrator. Extensive installation experience (RAC and stand-alone), administration, implementation, troubleshooting, Oracle 12c / 11g tuning, export / import, OEM grid control, Data Guard on Unix, Rman backup / restore, upgrade, migration , correction (RDBMS, GRID) PSU & CPU, Database migration. I like everything about the Oracle & DB2 database. For me, sharing is the best thing we can offer in this job. And learning is not an option but a duty for database administrators.

One comment

  1. Thank you bro, you are the best, it was a pleasure and still to be your student

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