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Oracle Academy Mid Term Exam Semester 1 Answers

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Test: Mid Term Exam Semester 1

Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 1

(Answer all questions in this section)

1. The first step in system development is to document the

requirements. Why? Mark for Review (1) Points Wrong. A blueprint for the database design is not needed. We

can just start coding straight away.

It clarifies what a business wants to accomplish, and provides measures for deciding if the system delivers all that is

required. (*)

It allows application development to be conducted without having to consider database design.

It keeps businesses honest. Correct

2. Information which was gained from data is the same as: (Choose

Two) Mark for Review

(1) Points (Choose all correct answers)

Knowledge (*) Raw Materials Intelligence (*)

There is no difference between data and information. Correct

3. The main subject areas taught by the Oracle Academy are:

Mark for Review (1) Points Computer Repairs

Database performance tuning

Data Modeling, SQL, and PL/SQL (*)

Systems programming and computer architecture Correct

4. The purpose or function of a database is to:

Mark for Review (1) Points Run multiple applications on multiple client-servers

Provide integrated software on fast processing servers Provide a structured way to access and manage data (*)

(2)

run solely as client-based software on personal computers Correct

Section 2

(Answer all questions in this section)

5. Attributes have Instances. True or False?

Mark for Review (1) Points True

False (*)

Incorrect. Refer to Section 2 Lesson 3.

6. Data models are drawn to show users the actual Data that their new system will contain; only Data listed on the Diagram can be entered into the Database. True or False?

Mark for Review (1) Points True (*)

False Correct

7. Which of the following statements about relationships are true?

(Choose Two) Mark for Review (1) Points (Choose all correct answers)

They become foreign keys in the database. (*)

They must be mandatory to be created in the database. They can be either mandatory or optional. (*)

They must exist between two different Entities. Correct

8. All of the following would be instances of the entity ANIMAL

SPECIES, except which one? Mark for Review (1) Points Dog Bird Elephant Leaf (*) Correct

9. All of the following could be attributes of an ENTITY called

PERSON, except which one? Mark for Review (1) Points Haircolor

(3)

Gender

Natacha Hansen (*) Correct

10. In a physical data model, a relationship is represented as a/an?

Mark for Review (1) Points Column Row Instance Foreign Key (*) Correct Section 2

(Answer all questions in this section)

11. Volatile attributes have special requirements and need special

attention when you are doing data modelling. True or False? Mark for Review (1) Points True (*)

False Correct Section 3

(Answer all questions in this section)

12. Matrix Diagrams show Optionality and Cardinality of the ERDs

they document. True or False? Mark for Review (1) Points True

False (*) Correct

13. Relationship Cardinality is important. True or False?

Mark for Review (1) Points True (*)

False Correct

14. Relationships represents something of significance to the

business. True or False? Mark for Review (1) Points True (*)

False

(4)

15. To identify an attribute as part of a unique identifier on an ER

diagram, the # symbol goes in front of it. True or False? Mark for Review (1) Points True (*)

False Correct

16. When reading a relationship between 2 entities, the relationship is

read both from left to right and right to left. True or False? Mark for Review (1) Points True (*)

False Correct Section 4

(Answer all questions in this section)

17. A business rule such as "We only ship goods after customers have completely paid any outstanding balances on their account" is best enforced by:

Mark for Review (1) Points Making the payment attribute null.

Making the payment attribute optional.

We need to trust our customers, and we know they will pay some day.

Hiring a programmer to create additional programming code to verify no goods are shipped until the account has been settled in full. (*)

Correct

18. All instances of a subtype may be an instance of the supertype

but does not have to. True or False? Mark for Review (1) Points True

False (*) Correct

19. When creating entities you must follow these rules: (Choose

Two) Mark for Review

(1) Points (Choose all correct answers)

Name them in Plural Name them in Singular (*) Exclude Attributes

Include Attributes (*) Correct

(5)

20. The "Other" subtype is mandatory. True or False?

Mark for Review (1) Points True

False (*) Correct

Section 4

(Answer all questions in this section)

21. You can only create relationships to a Supertype, not to a

Subtype. True or False? Mark for Review (1) Points True

False (*) Correct

22. A Supertype can have only one subtype. True or False?

Mark for Review (1) Points True

False (*) Correct Section 5

(Answer all questions in this section)

23. Relationships can be Redundant. True or False?

Mark for Review (1) Points True (*)

False Correct

24. If two entities have two relationships between them, these

relationships can be either _____________ or _____________ . Mark for Review (1) Points Redundant or Required (*)

Replicated or Required Resourced and Really Good Redundant and Replicated

Correct

25. What uncommon relationship is described by the statements: "Each DNA SAMPLE may be taken from one and only one PERSON and each PERSON may provide one and only one

Mark for Review (1) Points

(6)

DNA SAMPLE"

One to Many Optional One to Many Mandatory One to One Optional (*) Many to Many Mandatory

Correct

26. Which of the following pairs of entities is most likely to be

modeled as a M:M relationship? Mark for Review (1) Points CAR and WHEEL

TREE and BRANCH

PERSON and FINGERPRINT

TEACHER and SUBJECT AREA (*) Correct

27. Intersection Entities are at the Parent end of the newly created 1:M (Parent:Child) relationship; therefore, the original entities are the children of the newly created intersection entity. True or False?

Mark for Review (1) Points

True False (*)

Correct

28. Intersection Entities often have the relationships participating in

the UID, so the relationships are often barred. True or False? Mark for Review (1) Points True (*)

False Correct

29. What do you call the entity created when you resolve a M:M

relationship? Mark for Review (1) Points Intersection entity (*) Inclusion entity Recursive entity M:M entity Correct

30. A non-transferable relationship means the detail can be changed

to point to a new master. True or False? Mark for Review (1) Points True

(7)

False (*)

Incorrect. Refer to Section 5 Lesson 1.

Section 6

(Answer all questions in this section)

31. The candidate UID that is chosen to identify an entity is called the Primary UID; other candidate UIDs are called Secondary UIDs.

Mark for Review (1) Points Yes, this is the way UID's are named. (*)

No, it is not possible to have more than one UID for an Entity.

No, after UIDs are first sorted, the first one is called the Primary UID, the second is the Secondary UID, etc.

No, each Entity can only have one UID, the secondary one. Correct

32. A unique identifier must be made up of more than one attribute.

True or False? Mark for Review (1) Points True

False (*) Correct

33. An entity without repeated values is said to be in 1st Normal

Form. True or False? Mark for Review (1) Points True (*)

False Correct

34. No commercial database systems in the world will accept tables

that are not on 3rd Normal Form. True or False? Mark for Review (1) Points True

False (*) Correct

35. Any Non-UID attribute must be dependent upon the entire UID.

True or False? Mark for Review (1) Points True (*)

False

(8)

Section 7

(Answer all questions in this section)

36. Historical data must never be kept. True or False?

Mark for Review (1) Points True

False (*) Correct

37. All relationships participating in an arc must be mandatory. True

or False? Mark for Review (1) Points True

False (*) Correct

38. Which of the following would best be represented by an arc?

Mark for Review (1) Points TEACHER (Female, Bob)

DELIVERY ADDRESS (Home, Office) (*) PARENT (Girl, Bob)

STUDENT (Grade A student, Average Student) Correct

39. Arcs are Mandatory in Data modeling. All ERD's must have at

least one Arc. True or False? Mark for Review (1) Points True

False (*) Correct

40. An arc can also be modeled as Supertype and Subtypes. True or

False? Mark for Review (1) Points True (*)

False Correct

Section 7

(Answer all questions in this section)

41. Which of the following is NOT a relationship type?

Mark for Review (1) Points

(9)

Some to None (*) One to One One to Many Many to Many

Correct

42. A particular problem may be solved using either a Recursive Relationship or a Hierarchical Relationship, though not at the same time. True or False?

Mark for Review (1) Points True (*)

False Correct Section 9

(Answer all questions in this section)

43. Modeling historical data is optional. True or False?

Mark for Review (1) Points True (*)

False Correct

44. If a system includes the concept of time and it stores Start Dates, then End Dates becomes Mandatory. For each Start Date attribute you create, you MUST create an End Date attribute and it must be mandatory. True or False?

Mark for Review (1) Points

True False (*)

Correct

45. 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

46. 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

Mark for Review (1) Points

(10)

a delivery to take place on a Saturday or Sunday. What would be the best way to model this?

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. (*) Email current prices to all employees whenever a price changes.

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

noticeboard.

Allow them to enter whatever delivery charge they want. Correct

Section 10

(Answer all questions in this section)

47. Formal rules do exist for drawing ERD's. Even though they are only guidelines, you should always try to follow them. True or False?

Mark for Review (1) Points True (*)

False Correct

48. Which of the following statements are true for ERD's to enhance

their readability. (Choose Two) Mark for Review (1) Points (Choose all correct answers)

It is OK to break down a large ERD into subsets of the overall picture. By doing so, you end up with more than one ERD that, taken together, documents the entire system. (*) Avoid crossing one relationship line with another. (*) The crows feet (many ends) can point whichever way is the easiest to draw.

You must ensure that you have every single entity--even if hundreds of them exist--on one single, big diagram.

Correct

49. A datamodel containing generic modeling techniques must not be mixed in with non-generic models. The generic entities MUST be drawn on a diagram of their own. True or False?

Mark for Review (1) Points True

False (*) Correct

50. All datamodels must be transformed from specific to generic.

True or False? Mark for Review (1) Points

(11)

True False (*)

References

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