DBInstanceIdentifier: [required] The name of the DB instance to disassociate the IAM role from.
RoleArn: [required] The Amazon Resource Name (ARN) of the IAM role to disassociate from 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 disassociated from. For information about supported feature names, see DBEngineVersion.