Database Systems 6th Edition by Ramez Elmasri, Shamkant B. Navathe

تمرين 3

Consider a STUDENT relation in a UNIVERSITY database with the following attributes (Name, SSN, Local_phone, Address, Cell_phone, Age, GPA). Note that the cell phone may be from a different city and state (or province) from the local phone. A possible tuple of the relation is shown below: a. Identify the critical missing information from the LocalPhone and CellPhone attributes as shown in the example above. (Hint: How do call someone who lives in a different state or province?)
b. Would you store this additional information in the LocalPhone and CellPhone attributes or add new attributes to the schema for STUDENT?
c. Consider the Name attribute. What are the advantages and disadvantages of splitting this field from one attribute into three attributes (first name, middle name, and last name)?
d. What general guideline would you recommend for deciding when to store information in a single attribute and when to split the information.