Help Center> Relational Database Service> User Guide> Working with RDS for PostgreSQL> Instance Management> Changing a DB Instance Class
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Changing a DB Instance Class

Scenarios

You can change the CPU or memory (instance class) of a DB instance as required. If the status of a DB instance changes from Changing instance class to Available, the change is successful.

  • You can change the DB instance class only when your account balance is more than ¥0.
  • A DB instance cannot be deleted while its instance class is being changed.
  • You can scale up or down the compute and memory capacity of PostgreSQL DB instances as required.
  • If the primary DB instance has a read replica, the new DB instance class must be less than or equal to the read replica class. When changing the read replica class, ensure that the selected class is greater than or equal to the current primary instance class.

Procedure

  1. Log in to the management console.
  2. Click in the upper left corner and select a region and a project.
  3. Click Service List. Under Database, click Relational Database Service. The RDS console is displayed.
  4. On the Instance Management page, locate the target DB instance and choose More > Change Instance Class in the Operation column.

    Alternatively, click the target DB instance to go to the Basic Information page. In the DB Information area, click Change in the Instance Class field.

  5. On the displayed page, specify the new instance class and click Next.

    Figure 1 Changing a DB instance class

    Changing the DB instance class will cause the DB instance to reboot. Select off-peak hours to avoid service interruption.

    DB instances in a DCC only support the general-enhanced instance class.

  6. Confirm the specifications.

    • If you need to modify your settings, click Previous.
    • For pay-per-use DB instances, click Submit.

      To view the cost incurred by the DB instance class change, choose Billing > My Orders in the upper right corner.

    • For yearly/monthly DB instances:
      • If you intend to scale down the DB instance class, click Submit.

        The refund is automatically returned to your account. You can choose Billing > My Orders in the upper right corner to check the refund.

      • If you intend to scale up the DB instance class, click Pay Now. The scaling starts only after the payment is successful.

  7. View the DB instance class change result.

    Changing the DB instance class takes 5–15 minutes. During this period, the status of the DB instance on the Instance Management page is Changing instance class. After a few minutes, click the DB instance and view the instance class on the displayed Basic Information page to check that the change is successful.

    After the CPU or memory of a PostgreSQL DB instance is changed, the system will change the values of the following parameters accordingly:

    • shared_buffers
    • max_connections
    • maintenance_work_mem
    • effective_cache_size

Parent topic: Instance Management