This interface is used to get information from a SubCheckConstraintDescriptor.
A SubCheckConstraintDescriptor is used within the DataDictionary to
get auxiliary constraint information from the system table
that is auxiliary to sysconstraints.
version: 0.1 author: Jerry Brenner
Constructor for a SubCheckConstraintDescriptor
Parameters: constraintId - The UUID of the constraint. Parameters: constraintText - The text of the constraint definition. Parameters: referencedColumns - The columns referenced by the check constraint