Deck 2: The Relational Model

Question 1

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

Answer 1

False

Question 2

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

Answer 2

True

Question 3

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 3

True

Question 4

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

Question 5

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

Question 6

Surrogate key values have no meaning to the users.

Question 7

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

Question 8

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 9

Null values can cause problems because they are ambiguous.

Question 10

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

Question 11

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

Question 12

A key must be unique.

Question 13

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

Question 14

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

Question 15

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 16

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

Question 17

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

Question 18

Candidate keys may or may not be unique.

Question 19

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

Question 20

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

Question 21

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.

Question 22

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

Question 23

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

Question 24

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

Question 25

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.

Question 26

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

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

Question 27

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

Question 28

Microsoft Access forms can only contain data from one table.

Question 29

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 30

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

Question 31

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

Question 32

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 33

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

Question 34

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

Question 35

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 36

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

Question 37

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

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

Question 38

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 39

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

Question 40

Given the relations:
$\text { STUDENT (\underline{SID}, StudentName, Major, AdvisorID) }$
$\text { ADVISOR (\underline{AdvisorID}, AdvisorName, Office, Phone) }$
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 41

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 42

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 43

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 44

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 45

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

Question 46

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 47

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 48

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 49

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 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

Question 51

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 52

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

Question 53

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).

Question 54

Which of the following isnot 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 55

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

Question 56

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.

Question 57

In the normalization process,it isnotnecessary 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

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 59

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 60

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

Question 61

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

Question 62

Briefly describe the various tasks of the primary key.

Question 63

In practice,why would tables that have duplicate rows be allowed?

Question 64

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

Question 65

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

Question 66

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

Question 67

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

Question 68

Explain the terms relation,tuple,and attribute.

Question 69

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 70

Distinguish between the primary key and a candidate key.

Question 71

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

Question 72

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

Question 73

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

Question 74

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

Question 75

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

Question 76

What requirements must a two-dimensional table satisfy in order to be a relation?

Question 77

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

Question 78

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 79

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

Question 80

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