Figure 3: Supertype/subtype relationship and associated table mappings
Table Name	Column Name	Data Type		Length	Key Status		Required	Indexed	Column Description
PERSON	PersonID		Integer	4	Pkey	Yes		Yes	Unique identifier for each person
	FirstName		Text	20		Yes		Yes	Person's first or given name
	Minit		Text	1					Initial of person's middle name
	LastName		Text	30		Yes		Yes	Person's last or surname, family name
	Address		Text	60					Full residence address, including street number & name, city, state code, & zip code
	Phone		Text	30				Maybe	Contact phone number for this person, include area code
	Email		Text	60				Maybe	Contact email address for this person
EMPLOYEE	PersonID		Integer	4	Pkey, Fkey		Yes	Yes	Unique identifier for each person, link back to table PERSON
	EmpSSN		Text		12		Eventually	Yes	SSN for employee, required by tax law
	HireDate		Date						Date (mm/dd/yyyy) that employee was hired and began work
AUTHOR	PersonID		Integer	4	Pkey, Fkey		Yes	Yes	Unique identifier for each author, links back to table PERSON
	PayToOrderOf		Text	50					Who to make the paycheck out to
	PayToTaxID		Text	15					SSN or TaxID number for the paycheck
	PayToAddress		Text	60					Mailing address for the paycheck