Test: Mid Term Exam Semester 1 Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer. Semester 1 Mid Term Exam covers Sections 1-10 of Database Design. Section 4 (Answer all questions in this section) 1. 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 2. The "Other" subtype is mandatory. True or False? Mark for Review (1) Points True False (*) Correct 3. Which of the following are suitable Entity names? (Choose Two) Mark for Review (1) Points (Choose all correct answers) DOGS ANIMAL (*) ANIMALS DOG (*) Correct 4. 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. Business rules are important to data modelers. True or False? Mark for Review (1) Points True (*) False Correct Section 10 (Answer all questions in this section) 6. 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) Is is OK to break a big ERD down into subsets of the overall picture. This way you end up with more than one ERD, that together documents the entire system. (*) Try to avoid crossing lines (*) The crows feet (many ends) can point whichever way is the easiest to draw You must ensure you have all the entities on one single, big diagram, even if you have hundreds Correct 7. There is no point in trying to group your entities together on your diagram according to volume. Making a diagram pretty is a waste of time. True or False? Mark for Review (1) Points True False (*) Correct 8. Generic models are generally far more complex than a specific model. True or False? Mark for Review (1) Points True False (*) Correct 9. All datamodels must be transformed from specific to generic. True or False? Mark for Review (1) Points True False (*) Correct Section 9 (Answer all questions in this section) 10. All systems must include functionality to provide logging or journaling in conceptual data models. True or False? Mark for Review (1) Points True False (*) Correct Page 1 of 5***********************************************************************************Test: Mid Term Exam Semester 1 Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer. Semester 1 Mid Term Exam covers Sections 1-10 of Database Design. Section 9 (Answer all questions in this section) 11. You are doing a data model for a computer sales company, where the price of postage is dependent on what day of the week 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 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 price to all employees whenever the prices change. 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 12. Modeling historical data is Optional. True or False? Mark for Review (1) Points True (*) False Incorrect. Refer to Section 9 Lesson 1. 13. 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 14. 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 Section 3 (Answer all questions in this section) 15. Relationships represents something of significance to the business. True or False? Mark for Review (1) Points True (*) False Correct 16. Relationship Names are optional. True or False? Mark for Review (1) Points True False (*) Correct 17. All the Attributes in a system are just written on the ERD, and they all go in the Top Left Hand Corner of the paper. True or False? Mark for Review (1) Points True False (*) Incorrect. Refer to Section 3 Lesson 2. 18. When reading an ERD including Relationships you are said to be speaking: Mark for Review (1) Points Relationship-ish Gibberish ERDish (*) Entity-ish Correct 19. Matrix Diagrams are used to verify an ERD. True or False? Mark for Review (1) Points True (*) False Correct Section 5 (Answer all questions in this section) 20. 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 Page 2 of 5 *********************************************************************************Test: Mid Term Exam Semester 1 Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer. Semester 1 Mid Term Exam covers Sections 1-10 of Database Design. Section 5 (Answer all questions in this section) 21. Intersection Entities are at the Master end in the relationships between it and the original entities. So the original entities are details or children of the newly created intersection entity. True or False? Mark for Review (1) Points True False (*) Incorrect. Refer to Section 5 Lesson 3. 22. When you resolve a M-M you simply re-draw the relationships between the two original entities, no new entities are created. True or False? Mark for Review (1) Points True False (*) Correct 23. 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 False (*) Correct 24. A relationship from an entity back to itself is called a ___________ relationship. Mark for Review (1) Points Mandatory Recursive (*) Many to Many Optional Transferrable 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 DNA SAMPLE" Mark for Review (1) Points 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. Many to many relationships must be left in the Model. It is important to have them documented as M-M. True or False? Mark for Review (1) Points True False (*) Incorrect. Refer to Section 5 Lesson 2. Section 6 (Answer all questions in this section) 28. When is an entity in 2nd Normal Form? Mark for Review (1) Points When all non-UID attributes are dependent upon the entire UID. (*) When no attritibutes are mutually independant and fully independent on the primary key. When no attritibutes are mutually independent and all are fully dependent on the primary key. None of the Above. Correct 29. Would it be a good idea to model age as an attribute of STUDENT? Mark for Review (1) Points Yes Maybe it could stop us having to calculate someone's age every time we need it Sometimes No - it breaks the Normalization rules (*) Correct 30. There is no limit to how may UID's an entity can have. True or False? Mark for Review (1) Points True (*) False Incorrect. Refer to Section 6 Lesson 1. Page 3 of 5 **********************************************************************************Test: Mid Term Exam Semester 1 Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer. Semester 1 Mid Term Exam covers Sections 1-10 of Database Design. Section 6 (Answer all questions in this section) 31. The first UID for an entity is called the Primary UID, the second is called Secondary UID and so on. 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. Yes, but then it stops. No entities can have more than two UID's. No, each Entity can only have one UID, the secondary one. Correct 32. 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 33. An entity without repeated values is said to be on 1st Normal Form. True or False? Mark for Review (1) Points True (*) False Correct 34. Normalizing an Entity to 1st Normal Form is done by removing repeated or redundant attributes. True or False? Mark for Review (1) Points True (*) False Correct Section 7 (Answer all questions in this section) 35. 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 36. Primary UIDs are: Mark for Review (1) Points Something that each Entity should have, but is not mandatory (*) Useful as an alternative means of identifying instances of an entity, independent of their datatype Mandatory in data modeling Always comprised of numbers Correct 37. All relationships participating in an arc must be mandatory. True or False? Mark for Review (1) Points True False (*) Correct 38. Arcs are used to visually represent _________ between two or more relationships in an ERD. Mark for Review (1) Points Sameness Differences Exclusivity (*) Inheritance Correct 39. An arc can also be modeled as Supertype and Subtypes. True or False? Mark for Review (1) Points True (*) False Correct 40. A particular problem may be solved using either a Recursive Relationship or a Hierarchy, though not at the same time. True or False? Mark for Review (1) Points True (*) False Correct Page 4 of 5 ***********************************************************************************Test: Mid Term Exam Semester 1 Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer. Semester 1 Mid Term Exam covers Sections 1-10 of Database Design. Section 7 (Answer all questions in this section) 41. A relationship can be both Recursive and Hierachal at the same time. True or False? Mark for Review (1) Points True False (*) Correct 42. If Audit trail attributes are added to an entity they must be in the entities they are auditing. True or False? Mark for Review (1) Points True (*) False Correct 43. Modeling historical data can produce a unique identifier that always excludes dates. True or False? Mark for Review (1) Points True False (*) Correct Section 2 (Answer all questions in this section) 44. All of the following would be instances of the entity ANIMAL SPECIES except which? Mark for Review (1) Points Dog Bird Elephant Leaf (*) Correct 45. 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 46. Primary Unique Identifiers: (Choose Two) Mark for Review (1) Points (Choose all correct answers) Are Required. The data model is not complete until all entities have a Primary UID. (*) Distinguish each instance of an entity from all others (*) Are not required You may create more than one Primary Unique Identifier for an entity Correct 47. The entity/relationship model is created before the physical database design model? True or False? Mark for Review (1) Points True (*) False Correct 48. Volatile entities have special requirements and need special attention when you are doing data modelling. True or False? Mark for Review (1) Points True (*) False Correct 49. Data models are drawn to show users the actual Data their new system will contain. Only Data on the Diagram can be entered into the Database. True or False? Mark for Review (1) Points True (*) False Correct 50. Entity Relationship modeling is dependent on the hardware or software used for implementation, so you will need to change your ERD if you decide to change Hardware Vendor. True or False? Mark for Review (1) Points True False (*) Correct Page 5 of 5