Exam 1 - Chapter 2

अब Quizwiz के साथ अपने होमवर्क और परीक्षाओं को एस करें!

14) The use of surrogate keys usually complicates application programming since most DBMS products require the application program to generate surrogate key values.

Answer: FALSE

18) Normalization is the process of removing all functional dependencies from a relation.

Answer: FALSE

2) Every table is a relation, but not every relation is a table.

Answer: FALSE

20) Any table that meets the definition of a relation is said to be in second normal form.

Answer: FALSE

22) In the normalization process, it is not necessary to identify all the functional dependencies in a relation.

Answer: FALSE

24) In the normalization process, if you find a candidate key that is not a primary key, then you have determined that the relation needs to be broken into two or more other relations.

Answer: FALSE

26) Since Microsoft Access is a personal database, it is not subject to the modification problems that occur in other relational databases.

Answer: FALSE

28) In Microsoft Access, foreign keys are designated by using the Foreign Key button in the toolbar.

Answer: FALSE

29) In Microsoft Access, a relationship is created by dragging a foreign key column and dropping it on top of the corresponding primary key.

Answer: FALSE

30) Microsoft Access forms can only contain data from one table.

Answer: FALSE

5) In the relational model, each row of a table contains data that represents an attribute of the entity.

Answer: FALSE

8) Candidate keys may or may not be unique.

Answer: FALSE

73) In Microsoft Access, the Relationships window is accessed by using the ________ button on the Database tools command tab.

Answer: Relationship

72) In Microsoft Access, relationships between tables are built in the ________.

Answer: Relationships window.

10) To represent a relationship in the relational model, the primary key of one relation is placed into a second relation.

Answer: TRUE

12) Surrogate key values have no meaning to the users.

Answer: TRUE

15) Null values can cause problems because they are ambiguous.

Answer: TRUE

16) If the condition exists such that knowing the value of attribute X determines the value of attribute Y, then attribute Y is functionally dependent on attribute X.

Answer: TRUE

17) Given the functional dependency for the attributes of ENTITY1, X → (A, B, C), X is a candidate key for the relation ENTITY1 (A, B, C, X).

Answer: TRUE

19) To create a well-formed relation through normalization, every determinant must be a candidate key.

Answer: TRUE

23) In the normalization process, it is necessary to identify all the determinants in a relation.

Answer: TRUE

25) In the normalization process, if you find that every determinant in a relation is a candidate key, then you have determined that the relation is well formed.

Answer: TRUE

27) In Microsoft Access, relationships between tables are created in the Relationships window.

Answer: TRUE

3) Every relation is a table, but not every table is a relation.

Answer: TRUE

4) Every cell in a relation can hold only a single value.

Answer: TRUE

7) To be considered a composite key, a key must contain at least two attributes.

Answer: TRUE

9) The primary key is used both to identify unique rows in a relation and to represent rows in relationships.

Answer: TRUE

21) The first step of the normalization process is to identify all the candidate keys of a relation.

Answer: TRUE Diff: 1 Page Ref: 79

63) The unique keys that are not chosen to be the primary key are called ________ keys.

Answer: candidate

62) A key that contains two or more attributes is called a(n) ________ key.

Answer: composite

69) To be a well-formed relation, every ________ in the relation must be a candidate key.

Answer: determinant

64) When the primary key of one relation is placed in a second relation to represent a relationship, the attribute in the second relation is called a(n) ________ key.

Answer: foreign

67) The relationship between two attributes that denotes that if the value of the first attribute is known, then the value of the second attribute can be determined, is called a(n) ________.

Answer: functional dependency

61) A(n) ________ is one or more columns of a relation that is used to identify a row.

Answer: key

71) Although Microsoft Access is a personal database, the database tables in Access are still subject to ________ if they are not well-formed.

Answer: modification problems

68) The key that has been designated the ________ key of a relation functionally determines all the other attributes in the relation.

Answer: primary

74) To create a relationship in Microsoft Access, we drag and drop the ________ of a table.

Answer: primary key

65) A rule that requires every value in a foreign key to match values in the corresponding primary key is called a(n) ________ constraint.

Answer: referential integrity

70) Any table that meets the requirements of a(n) ________ is in first normal form.

Answer: relation

66) A(n) ________ is a unique, numeric value that is appended to the relation to serve as the primary key.

Answer: surrogate key

33) Which of the following terms is synonymous with "tuple"? A) Attribute B) Table C) Field D) Row E) Relation

Answer: D

35) Which of the following is true about a key? A) It may be unique. B) It may be non-unique. C) In may identify more than one row. D) Both A and B E) All of the above

Answer: E

37) A primary key is: A) required to be unique. B) used to represent rows in relationships. C) a candidate key. D) used to identify unique rows. E) All of the above

Answer: E

36) A key that contains more than one attribute is called a(n): A) composite key. B) complex key. C) multi-key. D) n-key. E) candidate key.

Answer: A

6) A key must be unique.

Answer: FALSE

13) Since surrogate keys are used to uniquely identify rows, their values are normally displayed prominently on all forms and reports for the users to see.

Answer: FALSE

43) Which of the following is not true of surrogate keys? A) They are meaningful to the users. B) They are numeric. C) They are usually generated by the DBMS. D) They are unique. E) They are usually hidden on forms and reports.

Answer: A

48) One important relational design principle is that: A) every determinant must be a candidate key. B) every candidate key must not be a determinant. C) every primary key must be a surrogate key. D) every determinant must be functionally dependent on the primary key. E) every primary key must be functionally dependent on every determinant.

Answer: A

51) The first step of the normalization process is to: A) identify all the candidate keys of a relation. B) identify all the foreign keys of a relation. C) identify all the functional dependencies of a relation. D) identify all the determinants of a relation. E) split the relation into two or more new relations.

Answer: A

55) In the normalization process, if you find that every determinant in a relation is a candidate key then you have determined that: A) the relation is well formed. B) the relation needs to be broken into two or more new relations. C) surrogate keys in the relation may not be correctly linked to other relations. D) the relation needs to have foreign keys added in order to be correctly linked to other relations. E) referential integrity constraints concerning the relation need to be established.

Answer: A

32) Which of the following is true about a relation? A) The order of the columns in a relation must go from largest to smallest. B) All entries in any column must be of the same kind. C) A relation may have duplicate column names. D) A relation may have duplicate rows. E) A relation may have multiple names.

Answer: B

34) Which of the following terms is synonymous with "relation"? A) Attribute B) Table C) Record D) Row E) Tuple

Answer: B

41) A rule that requires that the values in a foreign key must have a matching value in the primary key to which the foreign key corresponds is called: A) normalization. B) a referential integrity constraint. C) a key matching constraint. D) a functional dependency. E) synchronization.

Answer: B

46) Given the below functional dependency, MedicineCode → (MedicineName, ShelfLife, Manufacturer, Dosage) which of the following statements is not known to be true? A) MedicineCode is a determinant. B) MedicineName is a determinant. C) Manufacturer is functionally dependent on MedicineCode. D) ShelfLife is functionally dependent on MedicineCode. E) MedicineCode is a candidate key of the relation MEDICINE (MedicineName, ShelfLife, Manufacturer, Dosage, MedicineCode).

Answer: B

50) A table that meets the requirements of a relation is said to be in which normal form? A) Relational normal form (RNF) B) First normal form C) Second normal form D) Boyce-Codd normal form E) Domain/key normal form

Answer: B

52) In the normalization process, it is not necessary to: A) identify all the candidate keys of a relation. B) identify all the foreign keys of a relation. C) identify all the functional dependencies of a relation. D) identify all the determinants of a relation. E) determine if every determinant is a candidate key.

Answer: B

31) Which of the following is not true about a relation? A) A relation is a two-dimensional table. B) The cells of a relation must hold a single value. C) A relation may have duplicate column names. D) A relation may not have duplicate rows. E) The order of the rows of a relation is insignificant.

Answer: C

39) When the primary key of one relation is placed into a second relation, it is called a: A) field key. B) referential integrity. C) foreign key. D) candidate key. E) relocated key.

Answer: C

40) Given the relations: STUDENT (SID, StudentName, Major, AdvisorID) ADVISOR (AdvisorID, AdvisorName, Office, Phone) such that each student is assigned to one advisor, which of the following is true? A) SID is both a primary key and a foreign key. B) AdvisorName is a determinant. C) AdvisorID is a foreign key. D) Phone is a candidate key. E) Major is a candidate key.

Answer: C

49) During the normalization process, the remedy for a relation that is not well formed is to: A) create a surrogate key. B) create a functional dependency. C) break it into two or more relations that are well formed. D) combine it with another relation that is well formed. E) convert it into a list.

Answer: C

57) In Microsoft Access, relationships between tables are created: A) by the Relationships button on the Create command tab. B) by the Relationships button on the Home command tab. C) in the Relationships window. D) in the Table window of the table containing the primary key. E) in the Table window of the table containing the foreign key.

Answer: C

58) In Microsoft Access, a relationship between two tables is created: A) by entering the name of the foreign key in the appropriate table in Design View. B) by entering the name of the primary key in the appropriate table in Design View. C) by dragging the primary key column of one table onto the foreign key column of the other table in the Relationships window. D) by dragging the foreign key column of one table onto the primary key column of the other table in the Relationships window. E) by dragging the primary key column of one table onto the primary key column of the other table in the Relationships window.

Answer: C

44) In SQL Server, the starting value of a surrogate key is called the: A) Identity. B) Identity Increment. C) Identity Start. D) Identity Seed. E) Identity Property.

Answer: D

54) In the normalization process, if you find a candidate key that is not a determinant then you should: A) place the columns of the functional dependency in a new relation. B) make the determinant of the functional dependency the primary key of the new relation. C) leave a copy of the determinant as a foreign key in the original relation. D) All of the above E) None of the above

Answer: D

56) Although Microsoft Access is a personal database, it is still subject to the following modification problem(s): A) problems adding data. B) problems changing data. C) problems deleting data. D) All of the above E) None of the above

Answer: D

60) In Microsoft Access, the relationship between two tables is not actually created until: A) the OK button in the Create Relationships dialog box is clicked. B) the Create button in the Create Relationships dialog box is clicked. C) the OK button in the Edit Relationships dialog box is clicked. D) the Create button in the Edit Relationships dialog box is clicked. E) the Join button in the Edit Relationships dialog box is clicked.

Answer: D

38) A candidate key is: A) required to be unique. B) used to represent rows in relationships. C) a candidate to be the primary key. D) Both A and B E) All of the above

Answer: E

42) A surrogate key may be appropriate under which of the following circumstances? A) The available candidate keys would produce a lot of data duplication when representing relationships. B) The primary key is numeric. C) The available candidate keys would be prone to typographical errors. D) The available candidate keys have little meaning to the users. E) Both A and C

Answer: E

45) Which of the following is not true about null values? A) A null value can mean that the value is unknown. B) A null value is ambiguous. C) A null value can mean that the value is known to be blank. D) A null value can mean that no value for the field is appropriate. E) Null values cannot be avoided.

Answer: E

53) In the normalization process, if you find a candidate key that is not a primary key then you should: A) place the columns of the functional dependency in a new relation. B) make the determinant of the functional dependency the primary key of the new relation. C) leave a copy of the determinant as a foreign key in the original relation. D) All of the above E) None of the above

Answer: E

59) In Microsoft Access, referential integrity constraints are created: A) by setting a property value on the primary key in the table which contains it. B) by setting a property value on the foreign key in the table which contains it. C) by setting a property value on the primary key in the Relationships window. D) by setting a property value on the foreign key in the Relationships window. E) by checking the Enforce Referential Integrity check box in the Edit Relationships dialog box.

Answer: E

A) BuildingName → (RoomNumber, Capacity, Department) B) RoomNumber → (BuildingName, Department, Capacity) C) (Department, Capacity) → (BuildingName, RoomNumber) D) (BuildingName, Capacity) → (Department, RoomNumber) E) (BuildingName, RoomNumber) → (Capacity, Department)

Answer: E

75) In Microsoft Access, referential integrity constraints are created in the ________.

Answer: Edit Relationships dialog box

1) While the relational model for databases appears to hold much promise, few commercial databases have implemented it.

Answer: FALSE

11) When used to represent a relationship, the primary key must have the same name as the corresponding foreign key.

Answer: FALSE


संबंधित स्टडी सेट्स

MAT 120 Section 3.2 Conditional Probability and the Multiplication Rule

View Set

World History, Unit 1 Nationalism and Industrialism, Impact of the Industrial Age

View Set