Exam 3 System's Analysis
Which of the following is a purpose of logical model and physical database design?
Develop a logical database design from which we can do physical database design.
Which of the following is a method for representing human-computer dialogues?
Dialogue diagramming
A null value is used to represent the zero digit in a relation.
False
A primary key should be null.
False
A relation corresponds to a computer file.
False
A relation is said to be in second normal form when there are no transitive dependencies.
False
Analysts should use intelligent keys as identifiers.
False
Conceptual data modeling for an Internet-based electronic commerce application differs significantly from the process followed when analyzing the data needs for other types of applications.
False
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.
False
Display sequence refers to the way a user can move from one display to another.
False
Ideally, each data store on a primitive data-flow diagram will be an individual attribute.
False
Indexes should be used generously for databases that support transaction processing and other applications with heavy updating requirements.
False
Two different names used for the same attribute is called a homonym.
False
When a transcripting data error occurs, additional characters have been added to a field.
False
When an appending data error has occurred, characters have been lost from the field.
False
When designing textual output, you should use single spacing wherever possible.
False
When displaying textual information, use abbreviations and acronyms as often as possible.
False
When using the normalized relation notation, the primary key attribute is indicated by a dashed underline.
False
Which of the following best describes a business document that contains only predefined data?
Report
An audit trail is a record of the sequence of data entries and the date of those entries.
True
An entity instance is a single occurrence of an entity type.
True
Book, supplier, and state are examples of entity types.
True
Cardinality is the number of instances of entity B that can (or must) be associated with each instance of entity A.
True
Data security can be built into a file through encryption, passwords, or prohibiting users from directly manipulating a file.
True
Designing usable forms and reports requires your active interaction with users.
True
Gaining an understanding of the skills of the intended system users and the tasks they will be performing is invaluable when constructing a form or report.
True
Indexes should be used generously for databases intended primarily to support data retrievals.
True
On the Internet, form interaction is the standard method of gathering and displaying information.
True
Relationships are labeled with verb phrases.
True
The data on all forms and reports must consist of data elements in data stores and on the E-R data model for the application or else be computed from these data elements.
True
The value of a key attribute in a relation must uniquely identify every row in the relation.
True
When designing a form or report, which of the following is a fundamental question?
When is the form or report needed and used?
For a binary many-to-many relationship existing between entity types A and B:
a separate relation C is created; the primary key of relation C is a composite key consisting of the primary key for each of the two entities in the relationship.
Designing usable forms and reports requires:
active interaction with end users.
A binary one-to-many relationship in an E-R diagram is best represented by:
adding the primary key attribute (or attributes) of the entity on the one side of the relationship as a foreign key in the relation that is on the many side of the relationship.
The primary deliverable from the conceptual data-modeling step within the analysis phase is:
an entity-relationship diagram.
Making sure that all data and entry fields are clearly labeled corresponds to the following form and report guideline:
balance the layout.
A relationship between instances of two entity types is a:
binary relationship
Gathering the information you need for data modeling by reviewing specific business documents handled within the system describes the:
bottom-up approach.
Reviewing computer screens, reports, and business forms for the purpose of gaining an understanding of data is indicative of the:
bottom-up approach.
An attribute (or combination of attributes) that uniquely identifies each instance of an entity type defines:
candidate key.
When selecting an identifier, one should:
choose a candidate key that will not change its value over the life of each instance of the entity type.
The ability to provide field-level help is often referred to as:
context-sensitive help.
The sequence of interaction between a user and a system best describes a(n):
dialogue.
The technique where users must confirm their intention twice before being allowed to proceed is called:
double-confirmation.
A person, place, object, event, or concept in the user environment about which the organization wishes to maintain data refers to a(n):
entity
A single occurrence of an entity type defines:
entity instance.
On an entity-relationship diagram, a rectangle represents a(n):
entity.
An attribute that appears as a non key attribute in one relation and as a primary key attribute (or part of a primary key) in another relation is a:
foreign key.
A business document that contains some predefined data and may include some areas where additional data are to be filled in best describes a:
form
Form and report design:
generally follows a prototyping approach.
The alternative that goes beyond simply solving the problem in question and focuses instead on systems that contain many extra features users may desire is referred to as a:
high-end alternative.
Each of the following is a true statement about highlighting EXCEPT:
highlighting should be used as frequently as possible to draw the user to or away from certain information and to group together related information.
A candidate key that has been selected as the unique, identifying characteristic for an entity type is called a(n):
identifier
The minimum number of instances of entity B that may be associated with each instance of entity A defines the:
minimum cardinality of the relationship.
The primary deliverable from logical database design is:
normalized relations.
Testing to ensure that data conforms to a standard format is the purpose of the:
pictures/templates validation test.
A "many" maximum cardinality is noted on the E-R diagram by:
placing a crow's foot notation near the entity.
When designing interfaces and dialogues, you follow a:
prototyping approach.
Another name for a unary relationship is a:
recursive relationship
The integrity constraint that specifies that the value (or existence) of an attribute in one relation depends on the value (or existence) of the same attribute in another relation is called:
referential integrity.
A named two-dimensional table of data is a(n):
relation.
The most common style for a logical database model is the:
relational database model.
When each nonprimary key attribute is identified by the whole key, the relation is said to be in at least:
second normal form.
"Please wait while I open the file" is an example of:
status information.
Asking system users and business managers, "What are the subjects of the business?" would help determine:
the data entities and their descriptions.
When transforming an E-R diagram into normalized relations, the identifier of the entity type becomes:
the primary key of the corresponding relation.
The data modeling perspective that derives the business rules for a data model from an intimate understanding of the nature of the business, rather than from any specific information requirements in screens, reports, or business forms, is referred to as the:
top-down approach.
A relationship between the instances of one entity type is a:
unary relationship
On an entity-relationship diagram, the entity's identifier is:
underlined on an E-R diagram.
An entity whose primary key depends on the primary key of another entity is called a:
weak entity.
An ideal number of alternatives to generate is:
3
Which is the primary key(s) in the following STUDENT_GRADE(StudentID, CourseID, Grade)?
StudentID, CourseID
Testing to assure that data is of proper type is the purpose of the:
class or composition validation test.
For any relation R, if, for every valid instance of A, that value of A uniquely determines the value of B:
then B is said to be functionally dependent on A.
The dependence of nonprimary key attributes on other nonprimary key attributes best describes a:
transitive dependency.