Dana Halsey is chair of the Purebred Marmoset Society,which maintains a database of registered purebred marmosets and their breeding history.Originally,the database was stored on index cards,but recently Dana has been exploring the use of a computerized system.One file in the system will store the name,birth date,and other characteristics of all of the marmosets that have been registered.Each marmoset is uniquely identified by a registration number.A second file will contain data that link each marmoset to its male and female parents by means of their serial numbers.The primary key in the second file is:
A)Name
B)Birth date
C)Constructed from two foreign keys.
D)The primary key in the first file.

Question

Quizplus · Accepted Answer

The second file needs to link each marmoset to its male and female parents, which are identified by their serial numbers. Therefore, the primary key in the second file should be constructed from two foreign keys, one for the male parent and one for the female parent. This ensures that each record in the second file is unique and can be easily linked to the corresponding marmoset record in the first file. Using the name or birth date as the primary key may not be suitable since there may be multiple marmosets with the same name or birth date, and using the primary key in the first file may not allow for easy linking to the parent data.

Dana Halsey Is Chair of the Purebred Marmoset Society,which Maintains