Description
This statement creates a dblink to access a specified remote database. You must specify the dblink name and provide the username, tenant name, password, IP address, port number, and access type in the statement. For a reverse link, you must specify the username, tenant name, password, IP address, and port number of the local database. If you do not specify the access type, a dblink to access the remote OceanBase database is created by default.
If the remote database is an OceanBase database, you can specify its IP address and port number to be the IP address and port number of a specific OBServer node in the remote OceanBase cluster or the IP address and port number of an OceanBase cluster proxy. If the port number specified in the statement is the port number of an OceanBase cluster proxy and the proxy is deployed by ConfigUrl, you must specify the name of the cluster. For a reverse link, you must also specify the IP address and port number of a specific OBServer node in the local OceanBase cluster, along with the username, tenant name, and password.
If the remote database is an Oracle database, you must specify the access type as OCI, the oracle_sid, and set the tenant name to oracle.
Syntax
CREATE DATABASE LINK dblink_name CONNECT TO user_name@tenant_name
IDENTIFIED BY password_str [OB|OCI] HOST 'ip:port[/oracle_sid]' [CLUSTER cluster_name] [MY_NAME local_user_name@local_tenant_name
IDENTIFIED BY local_password_str HOST 'local_ip:local_port'];
Notes
| Parameter | Description |
|---|---|
| dblink_name | The name of the database link to be accessed. |
| user_name | The username of the remote database. |
| tenant_name | The tenant name of the remote database. If the remote database is an Oracle database, the tenant name is always oracle. |
| password | The password for logging in to the username of the remote database. If the password contains special characters other than digits and letters (~!@#%^&*_-+=|(){}[]:;,.?/ ), the password must be enclosed in double quotation marks to avoid syntax errors. |
| OB | OCI | Specifies the type of the remote database. OB indicates an OceanBase database, and OCI indicates an Oracle database. If you do not specify either parameter, an OceanBase database is assumed as the remote database. |
| ip | The IP address of the remote database. If the type of the remote database is OceanBase database, the IP address can be the IP address of the proxy of the remote OceanBase cluster or the IP address of an OBServer node in the cluster. If you specify the IP address of an OBServer node, the network between the local database and the specified OBServer node must be accessible. |
| port | The port number of the remote database. If the type of the remote database is OceanBase database, the port number can be the port number of the proxy of the remote OceanBase cluster or the port number of an OBServer node in the cluster. If you specify the port number of an OBServer node, the network between the local database and the specified OBServer node must be accessible. If the type of the remote database is Oracle database, the IP address is the IP address of the Oracle instance. |
| oracle_sid | The sid of the remote Oracle database. You must specify this parameter only when the type of the remote database is Oracle database. |
| cluster_name | The name of the remote OceanBase cluster. You must specify this parameter only when the port number specified in the statement is the port number of a proxy and the proxy is deployed by ConfigUrl. The parameter value must be enclosed in double quotation marks. |
| local_cluster_name | The name of the local OceanBase cluster. You must specify this parameter only when the port number specified in the statement is the port number of a proxy and the proxy is deployed by ConfigUrl. The parameter value must be enclosed in double quotation marks. |
| local_user | The username of the local database. |
| local_tenant | The tenant name of the local database. |
| local_password | The password for logging in to the username of the local database. If the password contains special characters other than digits and letters (~!@#%^&*_-+=|(){}[]:;,.?/ ), the password must be enclosed in double quotation marks to avoid syntax errors. |
| local_ip | The IP address of an OBServer node in the local OceanBase cluster. |
| local_port | The port number of an OBServer node in the local OceanBase cluster. |
Examples
Example 1: Create a dblink named ob_dblink_proxy to connect to OceanBase Database. The tenant of the remote database uses the default oracle user. The proxy is deployed by using ConfigUrl. The cluster name must be enclosed in double quotation marks to prevent the uppercase conversion of its letters.
obclient> CREATE DATABASE LINK ob_dblink_proxy CONNECT TO ob_testuser@oracle IDENTIFIED BY **1** OB HOST '10.XXX.XXX.XXX:30084' CLUSTER "ob***";
Query OK, 1 row affected
Example 2: Create a dblink named ob_dblink_reverse_link to connect to OceanBase Database with a reverse link. The tenant of the remote database is oracle.
obclient> CREATE DATABASE LINK ob_dblink_reverse_link CONNECT TO ob_testuser2@oracle IDENTIFIED BY **1** OB HOST '10.XXX.XXX.XXX:35305' MY_NAME local_ob_testuser@oracle identified by **2** host '10.XXX.XXX.XXX:35307';
Query OK, 1 row affected
Example 3: Create a dblink named orcl_dblink to connect to an Oracle database. The tenant of the remote database is oracle.
obclient> CREATE DATABASE LINK orcl_dblink CONNECT TO orcl_testuser@oracle IDENTIFIED BY **1** OCI HOST '10.XXX.XXX.XXX:1521/ORCL';
Query OK, 1 row affected