The database instance has the following parameter setting:
OS_AUTHENT_PREFIX = OPS$ OS_ROLES = FALSE REMOTE_OS_AUTHENT =
FALSE REMOTE_OS_ROLES = FALSE TIMED_OS_STATISTICS = 0
You have a local operating system user SKD. You create a database user OPS$SKD, and
then assign external authentication. The user OPS$SKD has the CREATE SESSION
privilege. What would you achieve by the above process?
A.
The database user OPS$SKD will be able to administer the database.
B.
The authentication detail for the database user OPS$SKD is recorded in the password file.
C.
The local operating system user SKD will be able to access the database instance without
specifying the username and password.
D.
The database user OPS$SKD has to login with the password of the local operating system user SKD
to access the database instance.
OS_AUTHENT_PREFIX specifies a prefix that Oracle uses to authenticate users attempting to connect to the server.
REMOTE_OS_AUTHENT : whether remote clients will be authenticated with the value of the OS_AUTHENT_PREFIX parameter. Default value: false
REMOTE_OS_ROLES specifies whether operating system roles are allowed for remote clients. The default value, false, causes Oracle to identify and manage roles for remote clients.
External Authentication: This method is to use an external database verification. Connect to Oracle DB user can not specify a user name or password situation. By means of a strict verification of the Advanced Security option , the system through the use of biometrics , x509 certificates and marking equipment to identify users. When using an external authentication database relies on the underlying operating system , network authentication service or external authentication service to restrict access to database accounts. Such a database will can use the login password .
If the operating system or network service permits , you can use external authentication to authenticate users. If using operating system authentication , set OS_AUTHENT_PREFIX initialization parameters , and use the prefix in Oracle user name. OS_AUTHENT_PREFIX parameter defines a prefix , Oracle DB will add this prefix before each user’s operating system account names. In order to achieve backward compatibility with earlier versions of Oracle software , the default value for this parameter is OPS $.
When a user tries to establish a connection, the user name Oracle DB will be prefixed with the Oracle database user name for comparison.
For example, suppose OS_AUTHENT_PREFIX set as follows:
OS_AUTHENT_PREFIX = OPS $, if a user’s operating system account named tsmith, the user needs to connect to Oracle DB and verified by the operating system, the Oracle DB will check whether there is a corresponding database user OPS $ tsmith, if the user exists, the user is allowed to establish a connection.
In all of the user (operating system has been performed to verify) reference must include the prefix OPS $ tsmith displayed.
NOTE: In some operating systems, text OS_AUTHENT_PREFIX initialization parameter is case-sensitive.
EXTERNAL AUTHENTICATION b/c OS_AUTHENT_PREFIX