This topic describes how to create a database link from a PolarDB O Edition cluster to a PolarDB O Edition cluster.

For more information about how to create a database link from a PolarDB O Edition cluster to a user-created Oracle database hosted on an Elastic Compute Service (ECS) instance, see Create a database link from to PostgreSQL.

Prerequisites

  • The source database and the destination database belong to the same Alibaba Cloud account.
  • The source database and the destination database are in the same region.
  • The kernel version of the PolarDB O Edition cluster is the latest kernel version. For information about how to upgrade the kernel version, see Upgrade the minor version.

Notes

You can create a maximum of 10 database links for each PolarDB O Edition cluster. Each database link consumes one database link quota of both the source cluster and the destination cluster.

Procedure

  1. Log on to the PolarDB console.
  2. In the upper-left corner of the console, select the region where the cluster is deployed.
  3. Find the cluster and click the cluster ID.
  4. In the left-side navigation pane, choose Settings and Management > Databases.
  5. On the Databases page, click the DBLinks tab in the upper part.
  6. Click Create DBLink and configure the following parameters.
    Parameter Description
    DBLink Name You can enter a custom name of the database link. The name must meet the following requirements:
    • The name must contain lowercase letters and can contain digits and underscores (_).
    • It must start with a lowercase letter and end with a letter or a digit.
    • It must be 1 to 64 characters in length.

    This name is required when you use the database link for cross-database queries.

    Source Instance Name The name of the current PolarDB O Edition cluster is used as the fixed value. You cannot modify this parameter.
    Source Database Name Select a database in the current PolarDB O Edition cluster from the drop-down list.
    Destination Instance Select a destination cluster for the database link from the drop-down list.
    Note You can only select a cluster deployed in the same region as the source cluster.
    Destination Account The account that is used to access the destination cluster. For more information about how to create an account, see Create database accounts.
    Destination Account Password The password of the account that is used to access the destination cluster.
    Destination Database Name Enter the database name of the destination cluster. For more information about how to create a database, see Databases.
  7. Click OK.

Related operations

API Description
CreateDBLink Creates a database link for a PolarDB O Edition cluster.
DescribeDBLinks Queries the database link information of a PolarDB O Edition cluster.