Section 4 Oracle Quiz

Test: Quiz: Supertypes and Subtypes

1. A supertype should have at least two subtypes. True or False?

• True (*)
• False

2. Which of the following is a TRUE statement about the diagram below?

• Every Z is either an A or a B
• Every B is a Z
• Every A is a Z
• Every A is a B (*)

3. All instances of the subtypes must be an instance of the supertype. True or False?

• True (*)
• False

4. A subtype can have a relationship not shared by the supertype. True or False?

• True (*)
• False

5. Which of the following are valid formats for an attribute?

• Character string (*)
• Decimal
• Number (*)
• HEX

6. All instances of the supertype are also instances of one of the subtypes. True or False?

• True (*)
• False

7. The “Other” subtype is best used:

• For instances that belong to the supertype and at least one other subtype.
• For a subtype that does not have any of the same attributes as the supertype to which it belongs.
• As an extra subtype to ensure that all instances of subtypes are mutually exclusive and complete. By having an “Other” subtype, all instances of the Supertype will be of one subtype type. (*)
• You should never have a subtype called Other.

8. Which of the following is the best scenario for using supertype/subtype entities:

• A pet store that sells small animals, because they each need different size cages and food.
• An ice cream store that sells ice cream in sugar cones and regular cones.
• A grocery store that gives customers a choice of plastic or paper bags.
• A vehicle dealership that sells cars, trucks and boats on trailers. (*)

9. When creating entities it is important to remember all of the following:

• Create a formal description. (*)
• Include attributes. (*)
• Do not use synonyms.
• Do use reserved words.

10. Which of the following is true about supertypes and subtypes?

• Instances that belong to two subtypes of the same supertype may be modeled as a one-to-one relationship between the two subtypes
• Subtypes inherit the relationships and attributes of the supertype (*)
• Subtypes may have no more than 2 levels of nesting
• Supertype and subtype entities must be mutually exclusive

Test: Quiz: Documenting Business Rules

1. How would you model a business rule that states that on a studentﾒs birthday, they do not have to attend their classes?

• Use a supertype
• Use a subtype
• Make the attribute Birthdate mandatory
• You cannot model this. You need to document it (*)

2. Why is it important to identify and document business rules?

• It allows you to create your data model, then check for accuracy. (*)
• It allows you to improve the client’s business.
• It ensures that the data model will automate all manual processes.
• None of the above

3. How should you handle constraints that cannot be modeled on an ER diagram?

• Always let the network architect handle them
• List them on a separate document to be handled programmatically (*)
• Explain them to the users so they can enforce them
• All constraints must be modeled and shown on the ER diagram

4. Which of the following is an example of a structural business rule?

• All employees must belong to at least one department. (*)
• Buildings to be purchased by the business must be current with earthquake building code.
• All overdue payments will have an added 10 % late fee.
• All products will have a selling price no less than 30 % greater than wholesale.

5. A business rule such as “All accounts must be paid in full within 10 days of billing” is best enforced by:

• Making the payment attribute mandatory.
• Making the relationship between CUSTOMER and PAYMENT fully mandatory and 1:1 on both sides.
• Creating a message to be printed on every bill that reminds the customer to pay within ten days.
• Hiring a programmer to create additional programming code to identify and report accounts past due. (*)

6. Business rules are important to data modelers because:

• A. They capture all of the needs, processes and required functionality of the business. (*)
• B. They are easily implemented in the ERD diagram.
• C. The data modeler must focus on structural rules, because they are easily represented diagrammatically and eliminate other rules that involve extra procedures or programming.
• D. Both A and C are true.

7. Only managers can approve travel requests is an example of which of the following?

• A structural business rule.
• A mandatory business rule.
• A procedural business rule. (*)
• An optional business rule.