Create Database Links from an Autonomous AI Database to a Publicly Accessible Oracle Database with a Wallet (mTLS)

You can create database links from an Autonomous AI Database to a target Oracle database that is on a public endpoint.

To use database links with Autonomous AI Database the target database must be configured to use TCP/IP with SSL (TCPS) authentication. Autonomous AI Databases use TCP/IP with SSL (TCPS) authentication by default, so you do not need to do any additional configuration in your target database to link to another Autonomous AI Database. Other Oracle databases must be configured to use TCP/IP with SSL (TCPS) authentication. See Configuring Secure Sockets Layer Authentication in Oracle Database 19c Security Guide or Oracle Database 26ai Security Guide for more information.

To create database links to a public target, the target Oracle Database must be accessible. Some databases may limit access (for example, using Access Control Lists). Make sure you enable your target database to allow access from your source database for the database link to work. If you limit access with Access Control Lists (ACLs), you can find the outbound IP address of your source Autonomous AI Database and allow that IP address to connect to your target database.

See How to Create a Database Link from Your Autonomous AI Database to a Database Cloud Service Instance for more information.

To create database links to a target Oracle database with a wallet (mTLS):

  1. Copy your target database wallet, cwallet.sso, containing the certificates for the target database to Object Store.

    Note the following for the wallet file:

    • The wallet file, along with the Database user ID and password provide access to data in the target Oracle Database. Store wallet files in a secure location. Share wallet files only with authorized users.

    • Do not rename the wallet file. The wallet file in Object Storage must be named cwallet.sso.

  2. Create credentials to access your Object Store where you store the wallet file cwallet.sso. See CREATE_CREDENTIAL Procedure for information about the username and password parameters for different object storage services.

  3. Create a directory on Autonomous AI Database for the wallet file cwallet.sso.

    For example:

     CREATE DIRECTORY *dblink_wallet_dir* AS '*directory_path_of_your_choice*';

    See Create Directory in Autonomous AI Database for information on creating directories.

  4. Use DBMS_CLOUD.GET_OBJECT to upload the target database wallet to the directory you created in the previous step, DBLINK_WALLET_DIR.

    For example:

     BEGIN
     DBMS_CLOUD.GET_OBJECT(
         credential_name => 'DEF_CRED_NAME',
         object_uri => 'https://objectstorage.us-phoenix-1.oraclecloud.com/n/*namespace-string*/b/*bucketname*/o/cwallet.sso',
         directory_name => '*DBLINK_WALLET_DIR*');
 END;
 /

    In this example, *namespace-string* is the Oracle Cloud Infrastructure object storage namespace and bucketname is the bucket name. See Understanding Object Storage Namespaces for more information.

    Note: The credential_name you use in this step is the credentials for the Object Store. In the next step you create the credentials to access the target database.

  5. On the Autonomous AI Database instance, create credentials to access the target database. The username and password you specify with DBMS_CLOUD.CREATE_CREDENTIAL are the credentials for the target database that you use to create the database link.

    Note: Supplying the credential_name parameter is required.

    For example:

     BEGIN
     DBMS_CLOUD.CREATE_CREDENTIAL(
         credential_name => 'DB_LINK_CRED',
         username => 'NICK',
         password => '*password*');
 END;
 /

    The characters in the username parameter must be all uppercase letters.

    This operation stores the credentials in the database in an encrypted format. You can use any name for the credential name.

  6. Create the database link to the target database using DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK.

    For example:

     BEGIN
     DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK(
         db_link_name => 'SALESLINK',
         hostname => 'adb.eu-frankfurt-1.oraclecloud.com',
         port => '1522',
         service_name => '*example*_medium.atpc.example.oraclecloud.com',
         ssl_server_cert_dn => 'CN=atpc.example.oraclecloud.com,OU=Oracle BMCS FRANKFURT,O=Oracle Corporation,L=Redwood City,ST=California,C=US',
         credential_name => 'DB_LINK_CRED',
         directory_name => '*DBLINK_WALLET_DIR*');
 END;
 /

    Users other than ADMIN require privileges to run DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK.

    If the wallet file in the directory specified with directory_name is not cwallet.sso, the procedure reports an error such as: ORA-28759: failure to open file.

  7. Use the database link you created to access data on the target database.

    For example:

     SELECT * FROM employees@SALESLINK;

For the credentials you create in Step 5, the target database credentials, if the password of the target user changes you can update the credential that contains the target user’s credentials as follows:

BEGIN
    DBMS_CLOUD.UPDATE_CREDENTIAL (
        credential_name => 'DB_LINK_CRED',
        attribute => 'PASSWORD',
        value => '*password*' );
END;
/

Where password is the new password.

After this operation, the existing database links that use this credential continue to work without having to drop and recreate the database links.

For additional information, see:

Database Link Notes with a Target Oracle Database

Provides notes for creating database links to a target Oracle database (when the target is not an Autonomous AI Database)

Notes for database links to other Oracle databases:

Related Content

DBMS_CLOUD_ADMIN Package