It is the method of verifying users to access the database. At the moment of creating the user, the verification method must be chosen: -

Password, which is the method used in the previous scenarios, so that the verification is via Oracle when trying to log in, the password is verified.

It is as follows (identified by password).

External: Verification is done through the operating system so that the user can connect to the database without entering the user name and password for the database, because the password for the database is not used in this type of verification. This type of verification requires initializing the variable OS_AUTHENT_PREFIX to contain a literal value, which is OPS$ originally. Of course, we can change it as we wish. We need this variable when verifying the user who wants to connect to the database. Let's assume that we changed the above variable to the value OBAY,

And the operating system user we are using is ADMINISTRATOR, then we need to create a user in the database named OBAYADMINISTRATOR and choose the verification method External.

Follow the steps with me:-

1- We make sure of the value of the variable OS_AUTHENT_PREFIX.

SHOW PARAMETER OS_AUTHENT_PREFIX; 

2- We change the variable to the value OBAY, for example.

ALTER SYSTEM SET OS_AUTHENT_PREFIX='OBAY' SCOPE=SPFILE; 

Of course we need to close the database and open it again.

3- Now we can check the value of the change.

SHOW PARAMETER OS_AUTHENT_PREFIX; 

4- Now we create the user OBAYADMINISTRATOR in the database.

CREATE USER OBAYADMINISTRATOR IDENTIFIED EXTERNALLY; 

Users in the database can be inquired about via:

DBA_USERS

You can also know the type of verification for the SESSION opened in the database

SELECT sid,authentication_type,osuser from v$SESSION_CONNECT_INFO; 

Now the user OBAYADMINISTRATOR can connect to the database directly without verifying the database, as verification is done through the operating system.