Database Design-Section 8 Quiz

Test: Section 8 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 8 Quiz
(Answer all questions in this section)

1. In a payroll system, it is desirable to have an entity called DAY with a holiday attribute when you want to track special holiday dates. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


2. If you have an entity that a DATE attribute, and other attributes that track characteristics of the date, you should create a DAY entity. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


3. Modeling historical data is optional. True or False? Mark for Review
(1) Points


True (*)


False



Incorrect Incorrect. Refer to Section 8 Lesson 2.


4. All systems must have an entity called WEEK with a holiday attribute, so you know when to give your employees a holiday. True or False? Mark for Review
(1) Points


True


False (*)



Incorrect Incorrect. Refer to Section 8 Lesson 2.


5. How do you know when to use the different types of time in your design? Mark for Review
(1) Points


It depends on the functional needs of the system . (*)


Always model time; you can take it out later if it is not needed.


You would first determine the existence of the concept of time and map it against the Greenwich Mean Time.


The rules are fixed and should be followed.



Correct Correct


Page 1 of 3 Next Summary


Test: Section 8 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 8 Quiz
(Answer all questions in this section)

6. Formal rules exist for drawing ERD's. You must always follow them, even if it results in an ERD that is difficult to read. True or False? Mark for Review
(1) Points


True


False (*)



Incorrect Incorrect. Refer to Section 8 Lesson 4.


7. In an ERD, it is a good idea to group your entities according to the expected volumes. By grouping high volume entities together, the diagrams could become easier to read. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


8. In an ERD, High Volume Entities usually have very few relationships to other entities. True or False? Mark for Review
(1) Points


True


False (*)



Incorrect Incorrect. Refer to Section 8 Lesson 4.


9. You must make sure all entities of a proposed system can fit onto one diagram. It is not allowed to break up a data model into more than one diagram. True or False? Mark for Review
(1) Points


True


False (*)



Incorrect Incorrect. Refer to Section 8 Lesson 4.


10. Which of the following scenarios should be modeled so that historical data is kept? (Choose two) Mark for Review
(1) Points

(Choose all correct answers)


TEACHER and AGE


CUSTOMER and ORDERS (*)


CUSTOMER and PAYMENTS (*)


BABY and AGE



Incorrect Incorrect. Refer to Section 8 Lesson 1.


Previous Page 2 of 3 Next Summary


Test: Section 8 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 8 Quiz
(Answer all questions in this section)

11. When modeling historical data the unique identifier is always made up of a barred relationship from the original two entities. True or False? Mark for Review
(1) Points


True


False (*)



Incorrect Incorrect. Refer to Section 8 Lesson 1.


12. Historical data must never be kept. True or False? Mark for Review
(1) Points


True


False (*)



Incorrect Incorrect. Refer to Section 8 Lesson 1.


13. You are doing a data model for a computer sales company where the price of postage depends upon the day of the week that goods are shipped. So shipping is more expensive if the customer wants a delivery to take place on a Saturday or Sunday. What would be the best way to model this? Mark for Review
(1) Points


Email current prices to all employees whenever a price changes.


Use a Delivery Day entity, which holds prices against week days, and ensure the we also have an attribute for the Requested Delivery Day in the Order Entity. (*)


Allow them to enter whatever delivery charge they want.


Update the prices in the system, print out the current prices when they change, and pin them on the company noticeboard.



Incorrect Incorrect. Refer to Section 8 Lesson 3.


14. What is the function of logging or journaling in conceptual data models? Mark for Review
(1) Points


Creates a fixed time for all events in a data model.


Gives a timestamp to all entities.


Allows you to track the history of attribute values, relationships, and/or entire entities (*)


Represents entities as time in the data model.



Incorrect Incorrect. Refer to Section 8 Lesson 3.


15. When a system requires that old values for attributes are kept on record, this is know as Journaling or Logging. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


Previous Page 3 of 3 Summary


Test: Section 8 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 8 Quiz
(Answer all questions in this section)

1. What is the function of logging or journaling in conceptual data models? Mark for Review
(1) Points


Gives a timestamp to all entities.


Creates a fixed time for all events in a data model.


Represents entities as time in the data model.


Allows you to track the history of attribute values, relationships, and/or entire entities (*)



Correct Correct


2. Which of the following is a logical constraint that could result from considering how time impacts an example of data storage? Mark for Review
(1) Points


An ASSIGNMENT may only refer to an EMPLOYEE with a valid employee record at the Start Date of the ASSIGNMENT. (*)


EMPLOYEE periods can overlap causing the database to crash.


End Date must be before the Start Date.


Dates must be stored with Time.



Correct Correct


3. When a system requires that old values for attributes are kept on record, this is know as Journaling or Logging. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


4. When a relationship may or may not be transferable, depending on time, this is know as a/an: Mark for Review
(1) Points


Arc.


Transferable Relationship


Conditional Non-transferable Relationship. (*)


Non-transferable Relationship.



Incorrect Incorrect. Refer to Section 8 Lesson 2.


5. How do you know when to use the different types of time in your design? Mark for Review
(1) Points


Always model time; you can take it out later if it is not needed.


It depends on the functional needs of the system . (*)


You would first determine the existence of the concept of time and map it against the Greenwich Mean Time.


The rules are fixed and should be followed.



Correct Correct


Page 1 of 3 Next Summary


Test: Section 8 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 8 Quiz
(Answer all questions in this section)

6. Conditional non-transferability refers to a relationship that may or may not be transferable, depending on time. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


7. In a payroll system, it is desirable to have an entity called DAY with a holiday attribute when you want to track special holiday dates. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


8. Which of the following would be a logical constraint when modeling time for a City entity? Mark for Review
(1) Points


Daily traffic patterns must be monitored to determine how many law enforcement officers are needed.


If you are doing a system for any French City, you would need security clearance.


Cites may change their names and/or country association if the borders of a country change. (*)


People are born in the city and people die in the city.



Correct Correct


9. You must make sure all entities of a proposed system can fit onto one diagram. It is not allowed to break up a data model into more than one diagram. True or False? Mark for Review
(1) Points


True


False (*)



Correct Correct


10. There is no point in trying to group your entities together on your diagram according to volume, and making a diagram look nice is a waste of time. True or False? Mark for Review
(1) Points


True


False (*)



Incorrect Incorrect. Refer to Section 8 Lesson 4.


Previous Page 2 of 3 Next Summary


Test: Section 8 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 8 Quiz
(Answer all questions in this section)

11. In an ERD, it is a good idea to group your entities according to the expected volumes. By grouping high volume entities together, the diagrams could become easier to read. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


12. Which of the following statements are true to enhance the readability of ERDs? (Choose Two) Mark for Review
(1) Points

(Choose all correct answers)


Relationship lines should not cross. (*)


Crossing relationship lines help the readability of the diagram.


It does not matter which way the crows feet (many ends of a relationship) point.


Crows feet (the many-ends of relationships) should consistently point the same direction where possible, either South & East or North & West (*)



Incorrect Incorrect. Refer to Section 8 Lesson 4.


13. Historical data must never be kept. True or False? Mark for Review
(1) Points


True


False (*)



Correct Correct


14. When modeling historical data the unique identifier is always made up of a barred relationship from the original two entities. True or False? Mark for Review
(1) Points


True


False (*)



Correct Correct


15. Which of the following scenarios should be modeled so that historical data is kept? (Choose two) Mark for Review
(1) Points

(Choose all correct answers)


TEACHER and AGE


BABY and AGE


CUSTOMER and PAYMENTS (*)


CUSTOMER and ORDERS (*)



Correct Correct


Previous Page 3 of 3 Summary


Test: Section 8 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 8 Quiz
(Answer all questions in this section)

1. Modeling historical data can produce a unique identifier that includes a date. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


2. Which of the following scenarios should be modeled so that historical data is kept? (Choose two) Mark for Review
(1) Points

(Choose all correct answers)


LIBRARY and BOOK (*)


LIBRARY and NUMBER OF BOOKS


STUDENT and AGE


STUDENT and GRADE (*)



Incorrect Incorrect. Refer to Section 8 Lesson 1.


3. Historical data must never be kept. True or False? Mark for Review
(1) Points


True


False (*)



Correct Correct


4. Which of the following statements are true to enhance the readability of ERDs? (Choose Two) Mark for Review
(1) Points

(Choose all correct answers)


Crows feet (the many-ends of relationships) should consistently point the same direction where possible, either South & East or North & West (*)


Crossing relationship lines help the readability of the diagram.


It does not matter which way the crows feet (many ends of a relationship) point.


Relationship lines should not cross. (*)



Correct Correct


5. In an ERD, High Volume Entities usually have very few relationships to other entities. True or False? Mark for Review
(1) Points


True


False (*)



Correct Correct


Page 1 of 3 Next Summary


Test: Section 8 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 8 Quiz
(Answer all questions in this section)

6. In an ERD, it is a good idea to group your entities according to the expected volumes. By grouping high volume entities together, the diagrams could become easier to read. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


7. No formal rules exist for drawing ERD's. The most important thing is to make sure that all entities, attributes, and relationships are documented on the diagram, and the diagram is clear and readable. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


8. When a system requires that old values for attributes are kept on record, this is know as Journaling or Logging. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


9. Why would you want to model a time component when designing a system that lets people buy bars of gold? Mark for Review
(1) Points


Sales people must determine where the gold is coming from.


You would not want to model this; it is not important.


The price of gold fluctuates and, to determine the current price, you need to know the time of purchase. (*)


The Government of your country might want to be notified of this transaction.



Incorrect Incorrect. Refer to Section 8 Lesson 3.


10. What is the function of logging or journaling in conceptual data models? Mark for Review
(1) Points


Creates a fixed time for all events in a data model.


Allows you to track the history of attribute values, relationships, and/or entire entities (*)


Gives a timestamp to all entities.


Represents entities as time in the data model.



Correct Correct


Previous Page 2 of 3 Next Summary


Test: Section 8 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 8 Quiz
(Answer all questions in this section)

11. All systems must have an entity called WEEK with a holiday attribute, so you know when to give your employees a holiday. True or False? Mark for Review
(1) Points


True


False (*)



Correct Correct


12. When you add the concept of time to your data model, your model becomes more complex. True or False? Mark for Review
(1) Points


True (*)


False



Correct Correct


13. How do you know when to use the different types of time in your design? Mark for Review
(1) Points


The rules are fixed and should be followed.


It depends on the functional needs of the system . (*)


You would first determine the existence of the concept of time and map it against the Greenwich Mean Time.


Always model time; you can take it out later if it is not needed.



Correct Correct


14. Which of the following would be a logical constraint when modeling time for a country entity? Mark for Review
(1) Points


People have births and deaths in their countries that must be tracked by the system.


Daily traffic patterns must be monitored to determine which countries are overcrowded.


If you are doing a system for France or Germany, you would need security clearance.


Countries may change their names and/or borders over a period of time. (*)



Correct Correct


15. When a relationship may or may not be transferable, depending on time, this is know as a/an: Mark for Review
(1) Points


Conditional Non-transferable Relationship. (*)


Arc.


Transferable Relationship


Non-transferable Relationship.



Correct Correct


Previous Page 3 of 3 Summary