Amazon Relational Database Service
User Guide (API Version 2014-10-31)

Modifying an Amazon RDS DB Instance

Most modifications to a DB instance can be applied immediately or deferred until the next maintenance window. Some modifications, such as parameter group changes, require that you manually reboot your DB instance for the change to take effect.


Some modifications result in an outage because Amazon RDS must reboot your DB instance for the change to take effect. Review the impact to your database and applications before modifying your DB instance settings.

To modify an Amazon RDS DB instance, follow the instructions for your specific database engine.

Using the Apply Immediately Parameter

When you modify a DB instance, you can apply the changes immediately. To apply changes immediately, you select the Apply Immediately option in the AWS Management Console, you use the --apply-immediately parameter when calling the AWS CLI, or you set the ApplyImmediately parameter to true when using the Amazon RDS API.

If you don't choose to apply changes immediately, the changes are put into the pending modifications queue. During the next maintenance window, any pending changes in the queue are applied. If you choose to apply changes immediately, your new changes and any changes in the pending modifications queue are applied.


If any of the pending modifications require downtime, choosing apply immediately can cause unexpected downtime.

When you choose to apply a change immediately, any pending modifications are also applied immediately, instead of during the next maintenance window.

If you don't want a pending change to be applied in the next maintenance window, you can modify the DB instance to revert the change using the AWS CLI and specify the --apply-immediately option.

Changes to some database settings are applied immediately, even if you choose to defer your changes. To see how the different database settings interact with the apply immediately setting, see the settings for your specific database engine.

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