Deck 9: Designing Databases

Question 1

The primary deliverable from logical database design is a conceptual model.

Answer 1

False

Question 2

Conceptual modeling is performed during systems design.

Answer 2

False

Question 3

A relation corresponds to a computer file.

Answer 3

False

Question 4

The selection of the appropriate storage format for each attribute from the logical database model is made during physical database design.

Question 5

Each row of a relation corresponds to a record that contains data values for an entity.

Question 6

The selection of data-storage technologies is made during the systems implementation and operation phase.

Question 7

The network model is the most common style for a logical database model.

Question 8

Normalization helps build a data model that is simple, not redundant, and requires minimum maintenance.

Question 9

One of the purposes of logical and physical database design is to choose data-storage technologies that will efficiently, accurately, and securely process database activities.

Question 10

Each column in a relation corresponds to an entity type.

Question 11

The network database model is a popular database technology for new information systems.

Question 12

In general, data structure refers to grouping attributes from the logical database model into physical records.

Question 13

A file organization is an arrangement of related records in secondary memory so that individual and groups of records can be stored, retrieved, and updated rapidly.

Question 14

One property of a relation is that entries in columns are from the same set of values.

Question 15

Referencing a relation, the sequence of columns cannot be interchanged without changing the meaning or use of the relation.

Question 16

When using the normalized relation notation, the primary key attribute is indicated by a dashed underline.

Question 17

During logic modeling, the normalized data requirements from all user interfaces are combined into one consolidated logical database model.

Question 18

During physical database design, relations from logical database design are translated into computer file specifications.

Question 19

Generally speaking, logical and physical database design is performed in parallel with other systems design steps.

Question 20

Object-oriented database models are the most frequently used database technologies for new information systems development.

Question 21

A relation is said to be in second normal form if the primary key consists of a combination key, and the nonkey attributes are partially dependent on the primary key.

Question 22

A corporal key is one assigned by the system.

Question 23

When two relations, A and B, have a many-to-many relationship, we create a separate relation, C, to represent this.

Question 24

Each entity type in an ER Diagram becomes an attribute.

Question 25

A binary 1 to many relationship in an ER Diagram is represented by adding the primary key of the entity on the one side of the relationship as a foreign key to the entity on the many side.

Question 26

The value of a key attribute in a relation must uniquely identify every row in the relation.

Question 27

The result of normalization is that every nonprimary key attribute depends upon the whole primary key and nothing but the primary key.

Question 28

If for every valid value of A the value of B is determined by the value of A, then B is functionally dependent on A.

Question 29

An attribute can be functionally dependent on more than one attribute.

Question 30

Transitive attributes are attributes that determine other attributes.

Question 31

A relation is said to be in second normal form if the primary key consists of only one attribute.

Question 32

The creation of a separate relation is sometimes required to represent a relationship.

Question 33

Referential integrity specifies that the value of an attribute of one relation depends on the existence of the same attribute in another relation.

Question 34

A well-structured relation contains data about two or more entities.

Question 35

For a binary one-to-one relationship between two entities, A and B, the primary key of A becomes a foreign key in B and the primary key in B becomes a foreign key in A.

Question 36

Normalization is based on an analysis of weak entities.

Question 37

A business rule is an integrity constraint specifying that the value of an attribute in one relation depends on the value of the same attribute in another relation.

Question 38

A relation is said to be in second normal form when there are no transitive dependencies.

Question 39

A relation is in second normal form if every nonprimary key attribute is functionally dependent on the whole primary key.

Question 40

A key can be redundant.

Question 41

View integration is the last step of logical database design.

Question 42

Two different names used for the same attribute is called a synonym.

Question 43

The hashed file organization determines the address for each row by using an algorithm.

Question 44

Indexes should be used generously for databases intended primarily to support data retrievals.

Question 45

Denormalization is the process of splitting or combining normalized relations into physical tables based on affinity of use of rows and fields.

Question 46

A null value is used to represent the zero digit in a relation.

Question 47

A default value is a value a field will assume unless an explicit value is entered for that field.

Question 48

Indexes should be used judiciously for databases that support transaction processing and other applications with heavy updating requirements.

Question 49

Efficient use of secondary storage and data processing speed are the two goals of physical table design.

Question 50

Sequential retrieval on the primary key is very fast with the hashed file organization.

Question 51

A data marker is a field of data that can be used to locate a related field or row of data.

Question 52

Denormalization reduces the chance of errors introduced by normalizing relations.

Question 53

Generally speaking, a physical table corresponds to a relation.

Question 54

When modeling a many-to-many unary relationship, the primary key of the relation representing the relationship is always singular.

Question 55

When using the sequential file organization, the addition of rows requires rewriting the file.

Question 56

Random key retrieval on the primary key is comparatively slow with the hashed file organization.

Question 57

A recursive foreign key is a foreign key in a relation that references the primary key value of the same relation.

Question 58

Sequential files are practical for random row retrievals.

Question 59

Two different names used for the same attribute is called a homonym.

Question 60

Multiple key retrieval is possible with the hashed file organization.

Question 61

Which of the following properties of a relation states that an entry at the intersection of each row and column is single-valued?

A) Entries in cells are simple.
B) Entries in columns are from the same set of values.
C) Each row is unique.
D) The sequence of rows is insignificant.
E) The sequence of columns can be interchanged.

Question 62

Combining all normalized user views into one consolidated logical database model refers to:

A) normalization.
B) requirements structuring.
C) file integration.
D) view integration.
E) logic modeling.

Question 63

Key physical database design decisions include:

A) choosing the storage format for each attribute from the logical database model.
B) grouping attributes from the logical database model into physical records.
C) arranging related records in secondary memory so that individual and groups of records can be stored, retrieved, and updated rapidly.
D) selecting media and structures for storing data to make access more efficient.
E) all of the above.

Question 64

During physical design, you consider:

A) the definitions of each attribute.
B) the descriptions of where and when data are entered, retrieved, deleted, and updated.
C) the expectations for response time and data integrity.
D) the descriptions of the file and database technologies to be used.
E) all of the above.

Question 65

The process of converting complex data structures into simple, stable data structures is referred to as:

A) normalization.
B) simplification.
C) structuring.
D) process modeling.
E) relational conversion.

Question 66

A relation that contains a minimum amount of redundancy and allows users to insert, modify, and delete the rows in a table without errors or inconsistencies is a(n):

A) independent relation.
B) simple relation.
C) unnormalized relation.
D) well-structured relation.
E) derived relation.

Question 67

The most common style for a logical database model is the:

A) relational database model.
B) hierarchical database model.
C) network database model.
D) object-oriented database model.
E) hybrid database model.

Question 68

File restoration can be achieved through backup copies of a file, audit trails, and row image files.

Question 69

A named two-dimensional table of data is a(n):

A) network.
B) tree structure.
C) relation.
D) tuple.
E) object.

Question 70

Data security can be built into a file through encryption, passwords, or prohibiting users from directly manipulating a file.

Question 71

Assume the structure of a relation is Employee (EmpID, Name, Dept, Salary).The number of attributes for this relation would:

A) be three.
B) be four.
C) be five.
D) be six.
E) vary depending upon the number of employees.

Question 72

Which of the following is a purpose of logical and physical database design?

A) Structure the data in stable structures that are not likely to change over time and that have minimal redundancy.
B) Develop a logical database design that reflects the actual data requirements that exist in the forms and reports of an information system.
C) Develop a logical database design from which we can do physical database design.
D) Translate a relational database model into a technical file and database design.
E) All of the above.

Question 73

Designing the database for an Internet-based electronic commerce application differs significantly from the process followed when designing the database for other types of applications.

Question 74

Which of the following is NOT a key step in logical database modeling and design?

A) Combine normalized data requirements from all user interfaces into one consolidated logical database model.
B) Compare the consolidated logical database design with the translated E-R model and produce, through view integration, one final logical database design for the application.
C) Model how data flow through an information system, the relationships among the data flows, and how data come to be stored at specific locations.
D) Translate the conceptual E-R data model for the application into normalized data requirements.
E) Using normalization principles, develop a logical data model for each known user view for the application.

Question 75

Using the normalized relation notation, an attribute of a relation which is the primary key of another relation is indicated by:

A) an underline.
B) a circle.
C) a dashed underline.
D) italics.
E) a double-lined ellipse.

Question 76

During logical database design, the work of all systems development team members is coordinated and shared through:

A) the project dictionary.
B) scheduled weekly meetings.
C) the project leader.
D) JAD sessions.
E) walkthroughs.

Question 77

Which of the following is NOT associated with logical and physical database design?

A) Structure the data in stable structures that are not likely to change over time and that have minimal redundancy.
B) The preparation of a final conceptual model and the implementation of the database
C) Develop a logical database design from which we can do physical database design.
D) Develop a logical database design that reflects the actual data requirements that exist in the forms and reports of an information system.
E) Translate a relational database model into a technical file and database design.

Question 78

Which of the following is NOT a true statement regarding a relation?

A) Each relation consists of a set of named columns and an arbitrary number of unnamed rows.
B) Each column in a relation corresponds to an attribute of that relation.
C) An entry at the intersection of each row and column has a single value.
D) Each row in a relation corresponds to an attribute of that relation.
E) The rows may be interchanged or stored in any sequence.

Question 79

A data model that represents data in the form of tables or relations is called a(n):

A) hierarchical database model.
B) network database model.
C) relational database model.
D) hybrid database model.
E) object-oriented database model.

Question 80

The primary deliverable from logical database design is:

A) normalized relations.
B) design specifications.
C) an updated Baseline Project Plan.
D) a list of alternatives design strategies.
E) a production system.