Deck 2: The Relational Model

Question 1

Which of the following terms is synonymous with "tuple"?

A) Attribute
B) Table
C) Field
D) Row
E) Relation

Answer 1

D

Question 2

Microsoft Access forms can only contain data from one table.

Answer 2

False

Question 3

A key must be unique.

Answer 3

False

Question 4

A double arrow notation,A →→ B,is used to indicate a multivalued dependency.

Question 5

Candidate keys may or may not be unique.

Question 6

Explain the possible interpretations of a null value.

Question 7

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

Question 8

Ensuring that every value of a foreign key matches a value of the corresponding primary key is an example of a referential integrity constraint.

Question 9

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.

Question 10

________ was the developer of the relational model for databases.

Question 11

Explain the terms relation,tuple,and attribute.

Question 12

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

Question 13

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

Question 14

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

Question 15

Which of the following is true about a key?

A) It may be unique.
B) It may be non-unique.
C) It can only identify one row.
D) Both A and B
E) None of the above

Question 16

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

Question 17

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

Question 18

Null values can cause problems because they are ambiguous.

Question 19

Which of the following terms is synonymous with "relation"?

A) Attribute
B) Table
C) Record
D) Row
E) Tuple

Question 20

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

Question 21

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).

Question 22

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

Question 23

Distinguish between the primary key and a candidate key.

Question 24

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

Question 25

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.

Question 26

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.

Question 27

Which of the following functional dependency diagrams accurately represents the following situation:
•A campus has many buildings.
•Each building has a unique name.
•Each building has many rooms.
•All rooms in any given building are numbered sequentially starting at "101."
•Each room has a certain capacity,although many rooms in the same building or different buildings may have the same capacity.
•Each room is assigned to a single department.
•A department may have many rooms in one or more buildings,each with the same or different capacities.

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)

Question 28

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.

Question 29

Explain the concept of a functional dependency.

Question 30

Surrogate key values have no meaning to the users.

Question 31

A primary key is ________.

A) not required to be unique
B) used to represent columns in relationships
C) a candidate key
D) always automatically generated by the DBMS
E) comprised of exactly one attribute

Question 32

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)________.

Question 33

A surrogate key may be appropriate under which of the following circumstances?

A) The primary key is not unique.
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) The relation only has one attribute.

Question 34

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

Question 35

Briefly describe the various tasks of the primary key.

Question 36

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

Question 37

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

Question 38

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

Question 39

A candidate key is ________.

A) never a primary key
B) a combination of two or more attributes
C) is always automatically generated by the DBMS
D) a candidate to be the primary key
E) None of the above

Question 40

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).

Question 41

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

Question 42

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

Question 43

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

Question 44

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

Question 45

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

Question 46

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

Question 47

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

Question 48

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

Question 49

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.

Question 50

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

Question 51

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

Question 52

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

Question 53

Explain the concept of a surrogate key.

Question 54

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) remove the determinant from the original relation
E) None of the above

Question 55

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

Question 56

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

Question 57

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

Question 58

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

Question 59

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

Question 60

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.

Question 61

What are the basic steps of the normalization process?

Question 62

In the normalization process,if you find a candidate key that is not a determinant then you should not ________.

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) rename the determinant to another attribute description
E) create a referential integrity constraint between the original relation and the new relation

Question 63

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

Question 64

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

Question 65

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.

Question 66

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

Question 67

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

Question 68

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

Question 69

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.

Question 70

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

Question 71

What is a multivalued dependency,and how do they affect the normalization process?

Question 72

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

Question 73

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

Question 74

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

Question 75

What is normalization?

Question 76

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

Question 77

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

Question 78

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

Question 79

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

Question 80

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