dbParameterGroupName
The name of the DB parameter group to associate with this DB instance. If you don't specify a value, then Amazon RDS uses the default DB parameter group for the specified DB engine and version.
This setting doesn't apply to RDS Custom DB instances.
Constraints:
Must be 1 to 255 letters, numbers, or hyphens.
The first character must be a letter.
Can't end with a hyphen or contain two consecutive hyphens.