Create Database Links from an Autonomous AI Database to an Oracle Database on a Private Endpoint

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

Note: Database links from an to a target Oracle database that is on a private endpoint are only supported in commercial regions and US Government regions. This feature is enabled by default in all commercial regions. This feature is enabled by default in US Government regions for newly provisioned databases. For existing US Government databases on a private endpoint, if you want to create database links from an Autonomous AI Database to a target in a US Government region, you can file a Service Request at Oracle Cloud Support and request to enable the private endpoint in government regions database linking feature. US Government regions include the following:

Depending on the type and the configuration of the target Oracle database:

Prerequisites for Database Links from Autonomous AI Database to Oracle Databases on a Private Endpoint

Lists the prerequisites to create database links from an Autonomous AI Database to a target Oracle database that is on a private endpoint.

To create a database link to a target Oracle database on a private endpoint:

Create Database Links to Oracle Databases on a Private Endpoint without a Wallet

Use DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK to create database links from an Autonomous AI Database to a target Oracle database that is on a private endpoint and connect without a wallet (TCP).

Note: This option is for target Oracle databases that are on a private endpoint and do not have SSL/TCPS configured.

Perform the prerequisite steps, as required. See Prerequisites for Database Links from Autonomous AI Database to Oracle Databases on a Private Endpoint for details.

To create a database link to a target database on a private endpoint using a secure TCP connection without a wallet:

  1. On Autonomous AI Database 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 used within the database link, (where the target database is accessed through the VCN).

    For example:

     BEGIN
      DBMS_CLOUD.CREATE_CREDENTIAL(
          credential_name => 'PRIVATE_ENDPOINT_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.

  2. 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 => 'PRIVATE_ENDPOINT_LINK',
          hostname => 'exampleHostname',
          port => '1522',
          service_name => '*exampleServiceName*',
          ssl_server_cert_dn => NULL,
          credential_name => 'PRIVATE_ENDPOINT_CRED',
          directory_name => NULL,
          private_target => TRUE);
 END;
 /

    For a target on a private endpoint, DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK supports specifying a single hostname with the hostname parameter. On a private endpoint, using an IP address, SCAN IP, or a SCAN hostname is not supported (when the target is on a public endpoint, CREATE_DATABASE_LINK supports using an IP address, a SCAN IP, or a SCAN hostname).

    When the target is an Oracle RAC database, use the rac_hostnames parameter to specify one or more hostnames with DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK. This allows you to take advantage of the high availability capabilities of Oracle RAC. Using an IP address, a SCAN IP, or a SCAN hostname in the rac_hostnames value is not supported.

    For example, with a target Oracle RAC database use the rac_hostnames parameter:

     BEGIN
      DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK(
          db_link_name => 'PRIVATE_ENDPOINT_LINK',
          rac_hostnames => '["sales1-svr1.*example*.adb.us-ashburn-1.oraclecloud.com",
                             "sales1-svr2.*example*.adb.us-ashburn-1.oraclecloud.com",
                             "sales1-svr3.*example*.adb.us-ashburn-1.oraclecloud.com"]',
          port => '1522',
          service_name => '*exampleServiceName*',
          ssl_server_cert_dn => NULL,
          credential_name => 'PRIVATE_ENDPOINT_CRED',
          directory_name => NULL,
          private_target => TRUE);
 END;
 /

    DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK does not support a value of localhost for the hostname or in the rac_hostnames parameter.

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

    As shown in the example, to create a database link with DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK to a target database on a private endpoint using a secure TCP connection without a wallet, all of the following are required:

    • The directory_name parameter must be NULL.

    • The ssl_server_cert_dn parameter must be NULL.

    • The private_target parameter must be TRUE.

  3. Use the database link you created to access data in the target database.

    For example:

     SELECT * FROM employees@PRIVATE_ENDPOINT_LINK;

For the credentials you create in Step 1, the Oracle 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.

See CREATE_DATABASE_LINK Procedure for additional information.

Create Database Links from Autonomous AI Database to Oracle Databases on a Private Endpoint with a Wallet (mTLS)

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

Note: This option is for target Oracle databases that have SSL/TCPS configured and that are on a private endpoint.

If the target Oracle database does not have SSL/TCPS configured, you have two options:

Perform the prerequisite steps, as required. See Prerequisites for Database Links from Autonomous AI Database to Oracle Databases on a Private Endpoint for details.

To create a database link to a target Oracle database on a private endpoint using TCP/IP with SSL (TCPS) authentication:

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

    Note: 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.

  2. Create credentials to access your Object Store where you store the 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 *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, 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 => '*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 Autonomous AI Database 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 used within the database link, (where the target database is accessed through the VCN).

    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 => 'PEDBLINK1',
     hostname => 'example1.adb.ap-osaka-1.oraclecloud.com',
     port => '1522',
     service_name => '*example_high.adb.oraclecloud.com*',
     ssl_server_cert_dn => '*ssl_server_cert_dn*',
     credential_name => 'DB_LINK_CRED',
     directory_name => '*WALLET_DIR*',
     private_target => TRUE);
 END;
 /

    For a target on a private endpoint, DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK supports specifying a single hostname with the hostname parameter. On a private endpoint, using an IP address, SCAN IP, or a SCAN hostname is not supported (when the target is on a public endpoint, CREATE_DATABASE_LINK supports using an IP address, a SCAN IP, or a SCAN hostname).

    When the target is an Oracle RAC database, use the rac_hostnames parameter to specify one or more hostnames with DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK. This allows you to take advantage of the high availability capabilities of Oracle RAC. Using an IP address, a SCAN IP, or a SCAN hostname in the rac_hostnames value is not supported.

    For example, with a target Oracle RAC database use the rac_hostnames parameter:

     BEGIN
   DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK(
     db_link_name => 'PEDBLINK1',
     rac_hostnames => '["sales1-svr1.*example*.adb.us-ashburn-1.oraclecloud.com",
                        "sales1-svr2.*example*.adb.us-ashburn-1.oraclecloud.com",
                        "sales1-svr3.*example*.adb.us-ashburn-1.oraclecloud.com"]',
     port => '1522',
     service_name => '*example_high.adb.oraclecloud.com*',
     ssl_server_cert_dn => '*ssl_server_cert_dn*',
     credential_name => 'DB_LINK_CRED',
     directory_name => '*WALLET_DIR*',
     private_target => TRUE);
 END;
 /

    DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK does not support a value of localhost for the hostname or in the rac_hostnames parameter.

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

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

    For example:

    ```sql SELECT * FROM employees@PEDBLINK1;

For the credentials you create in Step 5, the Oracle 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.

See CREATE_DATABASE_LINK Procedure for additional information.

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