Database Self Check

Lakukan tugas rumah & ujian kamu dengan baik sekarang menggunakan Quizwiz!

Organizational commitment to a database project is not necessary for its success.

Answer: FALSE

Organizations that utilize the file processing approach spend only 20 percent of development time on maintenance.

Answer: FALSE

The relational data model is no longer popular in the 21st century.

Answer: FALSE

A relational database establishes the relationships between entities by means of a common field.

Answer: TRUE

Although personal databases improve productivity, one risk is that data cannot be shared with other users.

Answer: TRUE

E. F. Codd developed the relational data model during the 1970s.

Answer: TRUE

Each member of a workgroup accesses data located on a database server.

Answer: TRUE

Enterprise modeling sets the range and general contents of organizational databases.

Answer: TRUE

File processing systems have been replaced by database systems in most critical business applications today.

Answer: TRUE

Which of the following is an integrated decision support database with content derived from various operational databases?

Data warehouse

In an E-R Diagram, strong entities are represented by double-walled rectangles.

False

In the figure below, one might want to create a single-attribute surrogate identifier to substitute for the composite identifier.

False

A business rule should be internally consistent.

True

One of the roles of a database analyst is to identify and understand rules that govern data.

True

One reason to use an associative entity is if the associative entity has one or more attributes in addition to the identifier.

True

Participation in a relationship may be optional or mandatory.

True

The E-R model is used to construct a conceptual model.

True

A rule that CANNOT be violated by database users is called a:

constraint.

One application of data warehouses is:

decision support.

An attribute whose value can be calculated from a related attribute is called a(n) ________ attribute.

derived

A(n) ________ is a set of values that may be assigned to an attribute

domain

The SDLC phase in which the detailed conceptual data model is created is the ________ phase.

analysis

An entity type that associates the instances of one or more entity types and contains attributes that are peculiar to the relationship is called a(n) ________.

associative entity

All of the following are properties of metadata EXCEPT:

processing logic.

If an identifier is not assigned, the default primary key for an associative relation consists of the two primary key attributes from the other two relations

true

In the figure below, each employee has exactly one manager.

true

When a regular entity type contains a multivalued attribute, two relations are created

true

When normalizing, the goal is to decompose relations with anomalies to produce smaller, well-structured relations

true

When two or more attributes describe the same characteristic of an entity, they are synonyms

true

A ________ relationship occurs between two instances of a single entity type.

unary

A logical representation of the data for an organization or for a business area is called a(n) ________.

entity-relationship model

A person, place, an object , an event or concept about which the organization wishes to maintain data is called a(n):

entity.

The entity integrity rule states that a primary key attribute can be null

flase

A(n) ________ is a constraint between two attributes or two sets of attributes

functional dependancy

An attribute that may have more than one meaning is called a(n)_____

homonym

When creating tables using the CREATE TABLE statement, NOT NULL constrains an attribute from being assigned a(n) ________ value

null

A constraint is a rule in a database system that can be violated by users.

Answer: FALSE

A well-structured database establishes the entities between relationships in order to derive the desired information.

Answer: FALSE

Database development begins with the design of the database.

Answer: FALSE

One reason for improved application development productivity with the database approach is that file design and low-level implementation details do not need to be handled by the application programmer.

Answer: TRUE

Prototyping is a type of rapid application development.

Answer: TRUE

A person is an example of an entity.

Answer: TRUE

An enterprise resource planning system integrates all functions of the enterprise.

Answer: TRUE

________ concentrate on determining the requirements for the database component of an information system.

Database analysts

The primary key of the many side migrates to the one side when transforming a one-to-many relationship

False

The three-schema approach includes which of the following schemas?

Internal

Which organizational function should set database standards?

None of the above

Data names should always relate to business characteristics.

True

Data rather than processes are the most complex aspects of many modern information systems

True

Relationships represent action being taken using a verb phrase.

True

When choosing an identifier, choose one that will not change its value often.

True

A property or characteristic of an entity is a(n) ________.

attribute

The period that can be considered a "proof of concept" time was the:

1960s.

E. F. Codd developed the relational model in the:

1970s.

Organizations that utilize the file processing approach spend as much as ________ of their IS development budget on maintenance.

80 percent

A(n) ________ is an attribute that uniquely identifies each row in a relation

primary key

Relational databases establish the relationships between entities by means of common fields included in a file called a(n):

relation.

A knowledge base of information on facts about an enterprise is called a(n):

repository.

With the database approach, data descriptions are stored in a central location known as a(n):

repository.

Database development begins with ________, which establishes the range and general contents of organizational databases.

enterprise data modeling

An anomaly is a type of flaw in the database server

f

An enterprise key is a foreign key whose value is unique across all relations

f

A ________ is an association between two or more terms.

fact

View integration is the process of merging relations together

false

When transforming a one-to-one relationship, a new relation is always created.

false

When transforming a unary many-to-many relationship to relations, a recursive foreign key is used

false

When transforming a weak entity, one should create one relation with both the attributes of the strong entity and the attributes of the weak entity.

false

A ________ is a statement that defines or constrains some aspect of the business.

business rule

Organizing the database in computer disk storage is done in the ________ phase.

design

A weak entity type is related to its owner by a(n) ________

identify relationship

Data that describe the properties of other data are:

none of the above.

One of the most popular RAD methods is:

prototyping.

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

relation

An entity-type name should be ________ to the organization.

specific

A ________ dependency is a functional dependency between the primary key and one or more nonkey attributes that are dependent upon the primary key via another nonkey attribute.

transitive

All projects move from the planning-enterprise modeling step to the planning-conceptual data modeling step of the systems development life cycle.

Answer: FALSE

An enterprise data model describes the scope of data for only one information system.

Answer: FALSE

An intranet utilizes Web-based technology to improve communication with parties outside of the organization.

Answer: FALSE

Characteristics of the structure of the database are generally changed during the implementation phase of the database development process.

Answer: FALSE

Data redundancy is used to establish relationships between data but is never used to improve database performance.

Answer: FALSE

Database development projects are never done in a bottom-up fashion.

Answer: FALSE

Database processing programs are coded and tested during the design stage of the systems development life cycle.

Answer: FALSE

Databases were developed as the first application of computers to data processing.

Answer: FALSE

In 1998, ANSI/SPARC published an import document describing the three-schema architecture.

Answer: FALSE

In two-tier database architectures, little functionality needs to be programmed into the client application.

Answer: FALSE

Systems analysts work directly with both management and users to analyze the business situation and develop detailed project specifications.

Answer: FALSE

The conceptual schema is always technology specific.

Answer: FALSE

The data that you are interested in capturing about an entity is called an instance.

Answer: FALSE

The internal schema consists of the physical schema and the enterprise data model.

Answer: FALSE

The physical structure and storage organization of the database is decided upon during the implementation phase of the systems development life cycle.

Answer: FALSE

The scope of an enterprise application is one workgroup or department.

Answer: FALSE

The steps of the systems development life cycle can only be viewed as a linear process.

Answer: FALSE

The term legacy system refers to a newly installed database management system.

Answer: FALSE

Visual programming tools such as Visual Basic have made prototyping more difficult.

Answer: FALSE

With the traditional file processing approach, each application shares data files, thus enabling much data sharing.

Answer: FALSE

A data model is a graphical system used to capture the nature and relationships among data.

Answer: TRUE

A data warehouse contains summarized and historical information.

Answer: TRUE

A modern database management system automates more of the backup and recovery tasks than a file system.

Answer: TRUE

A physical schema contains the specifications for how data from a conceptual schema are stored in a computer's secondary memory.

Answer: TRUE

An extranet uses Internet protocols to establish limited access to company data by the company's customers and suppliers.

Answer: TRUE

Applications built with a multitier architecture are meant to support departments.

Answer: TRUE

Cost and complexity are just two of the disadvantages of database processing.

Answer: TRUE

Data from prior systems is converted to the new system during the implementation phase of the systems development life cycle.

Answer: TRUE

Database architects establish standards for data in business units.

Answer: TRUE

Database maintenance is typically the longest step of the database development process.

Answer: TRUE

End users can often retrieve and display data easily with a relational database.

Answer: TRUE

In practice, databases today may contain either data or information.

Answer: TRUE

In prototyping, implementation and maintenance activities are repeated as necessary until the product is correct.

Answer: TRUE

Information is processed data.

Answer: TRUE

Multitier client/server database applications contain a business logic layer.

Answer: TRUE

Redundancy increases the risk of inconsistent data.

Answer: TRUE

Separation of metadata from application programs that use the data is called data independence.

Answer: TRUE

The data repository assists database administrators in enforcing standards.

Answer: TRUE

The external schema contains a subset of the conceptual schema relevant to a particular group of users.

Answer: TRUE

The failure to implement a strong database administrative function is the most common source of database failures in organizations.

Answer: TRUE

The most common way to support a group of individuals who work together on a project or group of similar projects is with a two-tier client/server database.

Answer: TRUE

The repository is populated during the analysis phase of the systems development life cycle.

Answer: TRUE

The systems development life cycle is the traditional methodology used to develop, maintain, and replace information systems.

Answer: TRUE

The user interface includes languages, menus, and other facilities by which users interact with various system components.

Answer: TRUE

Unplanned duplicate data files are the rule rather than the exception in file processing systems.

Answer: TRUE

Which of the following is software used to create, maintain, and provide controlled access to databases?

Database management system (DBMS)

A business rule is a statement of how a policy is enforced or conducted

False

A cardinality constraint tells what kinds of properties are associated with an entity.

False

A relationship instance is an association between entity instances where each relationship instance includes exactly one entity from each participating entity type.

False

A simple attribute can be broken down into smaller pieces.

False

A ternary relationship is equivalent to three binary relationships.

False

An affirmative entity is also called a relationship entity.

False

An entity type on which a strong entity is dependent is called a covariant entity.

False

Business rules are formulated from a collection of business ramblings.

False

In the figure below, the name of the relationship follows the guidelines for naming a relationship.

False

It is not permissible to associate attributes with relationships.

False

Most systems developers believe that data modeling is the least important part of the systems development process.

False

Some examples of attributes are: eye_color, weight, student_id, student.

False

The degree of a relationship is the number of attributes that are associated with it.

False

The intent of a business rule is to break down business structure.

False

The maximum criminality of a relationship is the maximum number of instances of entity B that may be associated with each instance of entity A.

False

The name used for an entity type should never be the same in other E-R diagrams on which the entity appears.

False

The purpose of data modeling is to document business rules about processes.

False

The relationship among the instances of three entity types is called a unary relationship.

False

Which of the following is NOT an advantage of database systems?

Redundant data

The need for consensus on data definitions is an example of which type of risk in the database environment?

Organizational conflict

________ is a tool even non-programmers can use to access information from a database.

Structured query language

Which of the following will interfere with access to operational databases?

Unstructured and unpredictable use of data

A business rule is a statement that defines or constrains some aspect of the business.

True

A good data definition is always accompanied by diagrams, such as the entity-relationship diagram

True

A referential integrity constraint is a rule that maintains consistency among the rows of two relations

True

A single occurrence of an entity is called an entity instance.

True

A time stamp is a time value that is associated with a data value.

True

An attribute whose values can be calculated from related attribute values is called a derived attribute.

True

An entity is a person, place, object, event, or concept in the user environment about which the organization wishes to maintain data.

True

An entity type name should always be a singular noun.

True

Enforcement of business rules can be automated through the use of software tools that can interpret the rules and enforce them.

True

In an E-R Diagram, an associative entity is represented by a rounded rectangle.

True

It is desirable that no two attributes across all entity types have the same name.

True

The relationship between the instances of two entity types is called a binary relationship.

True

While business rules are not redundant, a business rule can refer to another business rule.

True

A user view is how the user sees the data when it is produced.

Answer: FALSE

Personal databases are designed to support a small group of individuals working together on a project.

Answer: FALSE

Reduced program maintenance is an advantage of file processing systems.

Answer: FALSE

Repositories are always used in file processing systems.

Answer: FALSE

Development starts from scratch with the traditional file processing approach because new file formats, descriptions, and file access logic must be designed for each new program.

Answer: TRUE

Many of the disadvantages of file processing systems can also be limitations of databases.

Answer: TRUE

Metadata are data that describe the properties of other data.

Answer: TRUE

A co-dependency is a constraint between two attributes or two sets of attributes

False

Data names do not have to be unique.

False

When systems are automatically generated and maintained, quality is diminished.

False

Which of the following types of data can be stored in a database?

Voice, Letters, Numbers

Program-data dependence is caused by:

file descriptors being stored in each application.

A relation that contains no multivalued attributes is in ________ normal form.

first

An attribute in a relation that serves as the primary key of another relation in the same database is called a(n)_____

foreign key

A referential integrity constraint states that each ________ value must match a(n) ________ value in another relation or be blank

foreign key primary key

The SDLC phase in which database processing programs are created is the ________ phase.

implementation

Data processed in a way that increases a user's knowledge is:

information.

A primary key that consists of two or more attributes is called a(n) ________ key

composite

An attribute that can be broken down into component parts is called a(n) ________ attribute.

composite

A graphical system used to capture the nature and relationships among data is called a(n):

data model.

One disadvantage of file processing systems is:

limited data sharing.

An identifier should be chosen that has valid values and is not ________.

null

A data warehouse derives its data from:

Various operational data sources.

A user view is:

a logical description of some portion of the database.

A fact is an association between two or more terms.

True

A multivalued attribute may take on more than one value for a particular entity instance.

True

The relationship between a weak entity type and its owner is an identifying relationship.

True

Sample data are useful for developing prototype applications and for testing queries.

true

A relatively small team of people who collaborate on the same project is called a(n):

workgroup.

The SDLC phase in which every data attribute is defined, every category of data is listed and every business relationship between data entities is defined is called the ________ phase.

analysis

An error or inconsistency resulting from redundancy in tables is called a(n)______

anomaly

A database is an organized collection of ________ related data.

logically

A ________ is a functional dependency where one or more nonkey attributes are functionally dependent on part (but not all) of the primary key

partial functional dependancy

A weak entity must always have a(n) ________ that distinguishes the various occurrences of the weak entity for each owner entity instance

partial identifier

The number of entity types that participate in a relationship is called the ________ of the relationship.

degree

A(n) ________ is an attribute that uniquely identifies individual instances of an entity type.

identifier

A single occurrence of an entity type is called an entity ________.

instance

A centralized knowledge base of all data definitions, data relationships, screen and report formats, and other system components is called a(n):

repository.

A workgroup database is stored on a central device called a(n):

server.

A cascading delete removes all records in other tables associated with the record to be deleted

tRUE

A simultaneous relationship among the instances of three entity types is called a ________ relationship.

ternary

A ________ may be associated with any data value that changes over time when we need to maintain a history of those data values.

time stamp

A candidate key is an attribute, or combination of attributes, that uniquely identifies a row in a relation.

true

A partial functional dependency is a functional dependency in which one or more non-key attributes are functionally dependent on part (but not all) of the primary key.

true

A primary key is an attribute that uniquely identifies each row in a relation

true

A relation in fifth normal form may not contain any anomalies

true

A well-structured relation contains minimal redundancy and allows users to manipulate the relation without errors or inconsistencies

true

All values that appear in a column of a relation must be taken from the same domain

true

Data structures include data organized in the form of tables with rows and columns

true

One property of a relation is that each attribute within a relation has a unique name

true

The allowable range of values for a given attribute is part of the domain constraint

true

The columns of a relation can be interchanged without changing the meaning or use of the relation

true

The process of decomposing relations with anomalies to create smaller, well-structured relations is called ________.

normalization

All of the following are primary purposes of a database management system (DBMS) EXCEPT:

providing an integrated development environment.

The ________ states that no primary key attribute can be null

referential integrity constraint

A relationship name is a ________.

verb phrase

A composite key consists of only one attribute

F

An example of a term would be the following sentence: "A student registers for a course."

F.... Bawls

Which of the following is NOT a cost and/or risk of the database approach?

Improved responsiveness

An iterative methodology that rapidly repeats the analysis, design, and implementation phases of the SDLC is called:

RAD.

________ are established between entities in a well-structured database so that the desired information can be retrieved.

Relationships

The traditional methodology used to develop, maintain and replace information systems is called the:

Systems Development Life Cycle.

________ analyze the business situation and identify the need for information and information services to meet the problems or opportunities of the business.

Systems analysts

Which of the following is NOT an objective that drove the development and evolution of database technology?

The desire to require programmers to write all file handling functionality

An alternative name for an attribute is a(n)

alias

Databases may be more expensive to maintain than files because of:

all of the above.

In a file processing environment, descriptions for data and the logic for accessing the data are built into:

application programs.

CASE is a class of tools that:

automates the design of databases and application programs.

An attribute or combination of attributes that uniquely identifies a row in a relation is called a(n)_______

candidate key

A ________ specifies the number of instances of one entity that can be associated with each instance of another entity.

cardinality constraint

An identifier assigned to an associative entity is also called a cross-relation key

fa

Anomalies do not generally arise out of transitive dependencies

fa

CASE tools can model more complex data relationships, such as ternary relationships

fa

The most common source of database failures in organizations is:

failure to implement a strong database administration function.

Data integrity consists of powerful operations to manipulate data stored in relations

fal

A foreign key is a primary key of a relation that also is a primary key in another relation

false

A relation is in first normal form if it has no more than one multivalued attribute

false

A synonym is an attribute that may have more than one meaning

false

A transversal dependency is a functional dependency between two or more nonkey attributes

false

In the relational data model, associations between tables are defined through the use of primary keys

false

The relational data model does at this time directly support subtype/supertype relationships.

false

The truncate table statement in SQL creates a new table

false

There can be multivalued attributes in a relation.

false

Unlike columns, the rows of a relation may not be interchanged and must be stored in one sequence

false

Associative entities are also called ______

gerunds

Older systems that often contain data of poor quality are called ________ systems.

legacy

The first step in transforming EER diagrams into relations is to ________.

map regular entities

A(n) ________ is one that references the primary key values of the same relation

recursive foreign key

A(n) ________ is a rule that states that either each foreign key value must match a primary key value in another relation or the foreign key value must be null

referential integrity constraint

A meaningful relationship between entity types is called a(n) ________.

relationship type

Because applications are often developed independently in file processing systems:

unplanned duplicate data files are the rule rather than the exception.

A(n) ________ entity type exists independently of other entity types.

strong

Sometimes, associative entities have ________ identifiers assigned to them

surrogate

Languages, menus, and other facilities by which users interact with the database are collectively called a(n):

user interface.

A(n) ________ is often developed by identifying a form or report that a user needs on a regular basis.

user view


Set pelajaran terkait

ER diagram, EER Diagram, Relational Model

View Set

Principles of Marketing - Chapter 7

View Set

Noncontrolling Interest Consolidation

View Set

Astronomy test prep chapters 1-6

View Set

Chapter 1 Nutrition: food is more than something to eat.

View Set