DBInstanceIdentifier: [required] The name of the DB instance to associate the IAM role with.
RoleArn: [required] The Amazon Resource Name (ARN) of the IAM role to associate with the DB instance, for example arn:aws:iam::123456789012:role/AccessRole.
FeatureName: [required] The name of the feature for the DB instance that the IAM role is to be associated with. For information about supported feature names, see DBEngineVersion.