Deck 6: Database Design 2: Design Method

Question 1

The basic relationships among entities are: one-to-many, many-to-many, and one-to-one.

Answer 1

True

Question 2

A surrogate key is a primary key that consists of a column that uniquely identifies an entity.

Answer 2

False

Question 3

If you find that more than one table in your cumulative design has the same primary key, you should combine the tables to form a new table.

Answer 3

True

Question 4

A weak entity is an entity that depends on another entity for its own existence.

Question 5

When the user views are not clearly defined, you should consider each stated requirement as a separate user view.

Question 6

After you have completed the first two steps for a given user view, you can merge the results into the cumulative design.

Question 7

The first substep in representing the user view as a collection of tables is to determine entities and create a table for each.

Question 8

If no unique identifier is available for an entity, you can go without one.

Question 9

A foreign key is a column or collection of columns in one table that is required to match the value of the primary key for some row in another table, or be null.

Question 10

If each employee works in a single department, and each department has only one employee, the relationship between employees and departments is a one-to-many relationship.

Question 11

A design that supports all user views is called a constructive design.

Question 12

The simplest way to implement a one-to-one relationship is to treat it as a one-to-many relationship.

Question 13

The first step in creating a user view is to normalize the collection of tables.

Question 14

You create a many-to-many relationship by creating a new table whose primary key is the combination of the primary keys of the original tables.

Question 15

When combining third normal form tables, the resulting table will not be in third normal form when a column A in one user view determines a column B in a second user view, yet column A is not a column in the second user view.

Question 16

In a one-to-many relationship, the primary key of the "many" table becomes the foreign key of the "one" table.

Question 17

The information-level design methodology is completed independently of any particular DBMS that the organization will ultimately use.

Question 18

When determining the primary key of a table you must decide what properties are required to uniquely identify an entity.

Question 19

In an entity-relationship diagram, rectangles represent foreign keys.

Question 20

When you combine third normal form tables, the result will always be in third normal form.

Question 21

Convert the following table to first normal form:?Branch (BranchNum, BranchName, (BookCode, Title, OnHand) ) where BranchNum is the primary key

A) Branch (BranchNum, BranchName) where BranchNum is the primary key?Book (BookCode, Title) where BookCode is the primary key
B) Branch (BranchNum, BranchName) where BranchNum is the primary key
C) Book (BookCode, Title) where BookCode is the primary key
D) Branch (BranchNum, BranchName, BookCode, Title, OnHand ) where BranchNum and BookCode make the primary key

Question 22

Which of the following is an example of an enforcing restriction?

A) ensuring each row has a primary key
B) verifying there are no null values
C) verifying there is at least one secondary key in each table
D) ensuring values in foreign keys are legitimate

Question 23

In DBDL documentation, what element of a table is followed by an arrow pointing to the table identified by the element?

A) columns
B) alternate keys
C) secondary keys
D) foreign keys

Question 24

An alternative to the primary key of a table is listed with which abbreviation in DBDL?

A) SK
B) FK
C) PK
D) AK

Question 25

When implementing the physical-level design, for secondary keys, you must ensure that it is possible to retrieve data rapidly based on a value of which key?

A) primary
B) secondary
C) alternate
D) foreign

Question 26

If each employee works in a single department and each department has several employees, what is the relationship between departments and employees?

A) one-to-one
B) one-to-many
C) many-to-one
D) many-to-many

Question 27

Which type of key is usually an automatic numbering data type, such as the Access AutoNumber data type?

A) surrogate
B) artificial
C) natural
D) logical

Question 28

After the information-level design is completed, what is the next step?

A) The physical-level design
B) The top-down design
C) The bottom-up design
D) The logical-level design

Question 29

What is an entity that does not require a relationship to another entity for identification?

A) alternative entity
B) foreign entity
C) independent entity
D) single entity

Question 30

What type of primary key is system-generated and is usually hidden from users?

A) weak entity
B) surrogate key
C) natural key
D) artificial key

Question 31

Which of the following is used to improve performance in frequently used columns by maintaining a sort order but does not enforce constraints?

A) surrogate key
B) unique index
C) artificial key
D) nonunique index

Question 32

As you design the user view, which aspect of the table are the properties of the entities you choose?

A) rows
B) columns
C) data
D) DBMS

Question 33

Consider the following two tables where EmployeeNum is primary key in both tables. What is the result of combining the two tables??Employee (EmployeeNum, LastName, FirstName, WageRate, SocSecNum, DepartmentNum)?Employee (EmployeeNum, LastName, FirstName, Street, City, State, PostalCode)

A) Employee (EmployeeNum, LastName, FirstName, WageRate, SocSecNum, DepartmentNum, (Street, City, PostalCode) )
B) Employee (EmployeeNum, LastName, FirstName, WageRate, SocSecNum, DepartmentNum, Street, City, State, PostalCode)
C) Employee (EmployeeNum, LastName, FirstName, Street, City, State, PostalCode, WageRate, SocSecNum)
D) Employee (EmployeeNum, LastName, FirstName, WageRate, SocSecNum, DepartmentNum, EmployeeNum, LastName, FirstName, Street, City, State, PostalCode )

Question 34

What is the correct order of steps in the information-level design method??1. Normalize the tables.?2. Represent the user view as a collection of tables.?3. Merge the result into the cumulative design.?4. Represent all keys.

A) 1, 3, 2, 4
B) 2, 4, 3, 1
C) 2, 1, 4, 3
D) 1, 4, 2, 3

Question 35

What is a column that you create for an entity to serve solely as the primary key and that is visible to users?

A) synthetic key
B) weak entity
C) artificial key
D) natural key

Question 36

What type of key is also called a logical key?

A) surrogate
B) intelligent
C) secondary
D) synthetic

Question 37

What is a relationship that is necessary for identification?

A) objectifying relationship
B) merging relationship
C) identifying relationship
D) referential relationship

Question 38

Which of the following is a set of requirements that is necessary to support the operations of a particular database user?

A) user view
B) user table
C) user attribute
D) user field

Question 39

When a DBMS cannot enforce data and access restrictions, how should they be enforced?

A) by users when they are entering data using the DBMS
B) by peripheral programs written to access the database
C) by the operating system used to run the DBMS
D) by technicians who monitor database usage

Question 40

The crucial issue in making the determination between a single many-to-many-to-many relationship and two (or three) many-to-many relationships is the ____.

A) independence
B) primary key
C) redundancy
D) primary index

Question 41

In IDEF1X terminology, what is a subtype called?

A) catalog
B) category
C) entity
D) discriminator

Question 42

Columns that are of interest strictly for the purpose of retrieval are known as ____________________.

Question 43

As soon as you have completed Steps 1 through 3 for a given user view, you can merge the results into the __________________ design.

Question 44

For each table, you must identify the primary key and any alternate keys, secondary keys, and ____________________ keys.

Question 45

What does it mean when an entity has a minimum cardinality of one?

A) The entity is required in the relationship.
B) The entity is not required in the relationship.
C) The entity should not be in the relationship as an attribute.
D) The entity must be listed with all ones in the data fields.

Question 46

What is the term used in an E-R diagram that specifies the maximum number of entities that can participate in a relationship?

A) maximum cardinality
B) maximum entropy
C) highest ratio
D) highest entropy

Question 47

On an E-R diagram, what does the number closest to the relationship represent?

A) maximum entropy
B) minimum cardinality
C) midvalue ratio
D) highest entropy

Question 48

On an E-R diagram, ____________________ entities have rounded corners.

Question 49

A rectangle represents each _____________ in an E-R diagram.

Question 50

It is through foreign keys that you can create relationships among tables and enforce certain types of ____________________ constraints in a database.

Question 51

If an entity represented in a supertype table is not represented in the subtype table, what is this called in IDEF1X terminology?

A) foreign key
B) incomplete category
C) subtype anomaly
D) supertype discriminator

Question 52

A subtype ____________________ is the specific attribute that determines the subtype-supertype relationship.

Question 53

When designing a database, you might find it helpful to design a ____________ form to obtain the required information from users.

Question 54

Suppose you have the following two tables where EmployeeNum is the primary key in both tables. What can you say about the EmployeeBuilding table??Employee (EmployeeNum, LastName, FirstName)?EmployeeBuilding (EmployeeNum, BuildingName)?FK EmployeeNum -> Employee

A) The EmployeeBuilding table is a subtype of the Employee table.
B) The EmployeeBuilding table is a supertype of the Employee table.
C) The Employee table is a subtype of the EmployeeBuilding table.
D) BuildingName is a subtype discriminator.

Question 55

When are nulls used?

A) when a numeric value is zero
B) when a character value is blank
C) when a string contains a space
D) when a value is inapplicable

Question 56

During the ____________________-level design, designers must consider the characteristics of the particular DBMS that the organization will use.

Question 57

What does it mean when an entity has a minimum cardinality of zero?

A) The entity has a mandatory role in the relationship.
B) The entity is not required in the relationship.
C) The entity should not be in the relationship as an attribute.
D) The entity must be listed with all zeros in the data fields.

Question 58

____________________ key restrictions determine the relationships between tables.

Question 59

If a many-to-many-to-many relationship is created when it is not appropriate to do so, how can the problem be corrected?

A) by converting to 1NF
B) by converting to 2NF
C) by converting to 3NF
D) by converting to 4NF

Question 60

What is an entity that can serve as the relationship between other entities called?

A) composite entity
B) complex entity
C) complicated entity
D) circular entity

Question 61

List the types of information that must be included on a survey form in order for it to be considered valuable to the design process.

Question 62

____________________ refers to the number of items that must be included in a relationship.

Question 63

To obtain information about ____________________ dependencies you might ask users questions such as: "If you know a particular employee number, can you establish other information, such as employee name?"

Question 64

When the existence of one entity depends on the existence of another related entity, there is an existence ____________________.

Question 65

An entity in a relationship with minimum cardinality of zero plays a(n) ____________________ role in the relationship.

Question 66

List the steps that must be followed for each user view, as suggested by the information-level design methodology.

Question 67

A(n) ____________________ is essentially both an entity and a relationship and is represented in an E-R diagram by a diamond within a rectangle.

Question 68

Describe the different types of primary keys.

Question 69

The E-R model (also called ERM) uses diagrams to represent the high-level abstract and conceptual representation of data, along with entities, attributes, and ____________________.

Question 70

How can you attempt to avoid the problem of creating a table that is not in third normal form?

Question 71

A(n) ____________________ is a special value that represents the absence of a value in a field.

Question 72

An entity with a minimum cardinality of one plays a(n) ____________________ role in the relationship.

Question 73

In IDEF1X, _______________ categories are represented by two horizontal lines below the category symbol.

Question 74

You can recognize entity subtypes by the fact the primary key is also a(n) ____________________.

Question 75

What is an existence dependency? Provide an example.