How do I modify the values of an Amazon RDS DB parameter group?

Last updated: 2019-04-23

How do I modify the values of an Amazon Relational Database Service (Amazon RDS) DB parameter group? How can I resolve an issue that I experienced when trying to change my Amazon RDS DB instance configuration?

Short Description

You can modify parameter values in a custom DB parameter group, but you can't change the parameter values in a default DB parameter group. If you're experiencing an issue while modifying the value of a DB parameter group, review the following common issues:

  • If you use commands such as SET, you might receive an error, because these commands can't be used to update DB instance configurations.
  • If you can't update the DB instance configuration, it might be because you can't change the values of a default DB parameter group.
  • If you changed the parameter values but the changes haven't gone into effect, it might be because not all modifications are applied immediately.
  • If you can't modify DB parameters under any circumstances, it might be because the parameter's property value for Is Modifiable is false.

For more information, see Working with DB Parameter Groups.

Resolution

To change an Amazon RDS DB instance configuration, you must change the parameter values of the DB parameter group for your DB instance. To modify a DB instance configuration, follow these steps:

  1. Create a DB Parameter Group.
  2. View the Parameter Values for a DB Parameter Group to confirm that the Is Modifiable property is true.
  3. Modify the Parameters in a DB Parameter Group.

After the custom DB parameter group is applied (by using Apply immediately or by using Apply during the maintenance window), the DB parameter group status for that instance changes to pending-reboot in Amazon RDS console. This means that the parameter group is applied, but the parameter changes haven't been applied yet. After a manual reboot of the DB instance, the parameter changes are applied and the DB parameter group status for the instance changes from pending-reboot to in-sync.

Instances require a manual reboot in the following circumstances:

  • If you replace the current parameter group with a different parameter group.
  • If you modify and save a static parameter in a custom parameter group.

Static parameter change takes effect after you manually reboot the DB instance. For more information, see Modifying Parameters in a DB Parameter Group.

A reboot doesn't occur in the following circumstances:

  • If you modify a dynamic parameter in a custom parameter group.

For more information, see Amazon RDS DB Parameter Changes Not Taking Effect.