C175 Practice Test

1st Normal Form

1 value per field

Affinity grouping in data mining

Between objects

Attribute

Characteristic of an entity

Data (file structure)

Consists of raw facts and figures

True

DBMS is the only way to access data in database

False

DBMS reveals much of the database complexity to programs and users

Operational database

Data warehouse contains historical data obtained from the ______

The SQL SELECT DISTINCT operator ____.

Eliminates duplicate rows in the output of an SQL SELECT command

The SQL SELECT LIKE operator ____.

Involves the use of wildcards

Consider relations X and Y, each representing one of two entities in a many-to-many binary relationship. Relation Z is the additional relation created to store the many-to-many relationship. Intersection data ____.

Is stored in relation Z

Candidate key

Minimal key to being a primary key (SSN)

3rd Normal Form

No field dependent on another field (remove transitive dependencies)

End-user data

Raw facts of interest to the end user

Data

Raw facts that have not been processed into knowledge

Tuple

Rows

Desktop db

Single user db that runs on personal pc

Entity types

What is distinct about ER diagrams?

An entity is _____ in the business environment.

an object or event

Rebuilding a database after it is destroyed by a natural disaster is an aspect of _____.

backup and recovery

A data definition language (DDL) ____.

specifies what tables will be in the database, what attributes will be in the tables, and which attributes will be indexed

What is the positioning and meaning for Cardinality and Modality on an ER model?

- Cardinality is the outer symbol; represents the maximum. - Modality is the inner symbol; represents the minimum.

A data manipulation language (DML) is capable of ____.

1. inserting new records or rows into a relation 2. deleting records or rows of a relation 3. retrieving data from a relation

Structured Query Language (SQL) ____.

1. is capable of retrieving data from a relational database 2. is capable of defining the tables, attributes, and indexes of a relational database

Entity

A person, place, thing, concept, or event for which data can be stored

2nd Normal Form

All fields dependent on primary field

Associative Entity

An entity designed to transform an M:N relationship into two 1:M relationships.

An attribute is a _____.

Characteristic of an entity

Semistructured

Classification of most data encountered

An entity set is a _____.

Collection of entities of the same type

Record

Contains a set of fields that describes a person, place, or thing

Field

Contains all the information within the table appropriate to a particular entity

Metadata

Data about data, through which the end-user data is integrated and managed

Intersection data

Describes the relationship between two entities in a many-to-many relationship

Anomaly

Develops when all required changes in redundant data are not made successfully

Entity-Relationship (E-R) model

Diagramming technique for entities, their attributes, and their relationships

False (decreases security risk)

Dissadantage of DBMS is increased risk of security breaches

Relational Model

Each relation (table) is conceptually represented as a two-dimensional structure of intersecting rows and columns. The relations are related to each other through the sharing of common entity characteristics (values in columns).

Binary relationship is between two

Entity types

In the SQL SELECT command, the table(s) involved in the query is (are) specified in the ____ clause.

FROM

Hashed file

Files are encrypted using functions that convert data consisting of various formats into numeric values. This allows for faster data lookup without the use of an index file.

Heap files

Files containing an unsorted set of records that are uniquely identified by a record id which allows them to be inserted or deleted using that id.

Flat files

Files having no internal hierarchy

Index files

Files that store a list of lookup field values from a data file

Each student at a university takes many courses; each course is taken by many students. The semester that a student took a course and the grade that the student received in the course is called _____ data.

Intersection

The SQL SELECT IN operator ____.

Involves looking for character strings and can be used instead of a series of OR operators

One-to-one binary relationship

Involves two entity types

Why use index?

Leverage pointer in db

Cardinality of a relationship

Maximum number of entities that can be involved in the relationship

Modality of a relationship is

Minimum number of entities that can be involved in the relationship

Many-to-many binary relationship allows an occurrence of one entity type to be associated with

Multiple occurrences of another entity type

One-to-many binary relationship allows an occurrence of the entity type on the "one side" of the relationship to be associated with

Multiple occurrences of the entity type on the "many side" of the relationship

Domain of values

Necessary for primary key to match with corresponding foregin key

DBMS (database management systems)

Needed to manage structure, control access to data

Unary Relationship

Occurrence of an entity type with other of the same entity type.

Single user db

One user at a time

Each professor has one office. The relationship between campus buildings and professors is a _____ relationship.

One-to-many binary (1 can have many)

Each professor is entitled to one parking space. This is an example of a _____ relationship.

One-to-one binary

Domain

Range of values

What is a description of a particular entity?

Record occurrence

Referential Integrity

Reference to data in 1 relation is based on values in another relation

Association between entities is

Relationship

Binary Relationship

Relationship between two entity types.

Which of the following does NOT change the contents of a file? a. retrieve b. insert c. delete d. update e. all of the above

Retrieve

Extraction/Transformation/Loading (ETL)

Retrieving data from original data sources (extraction), manipulating the data into an appropriate form (transformation), and storing the data in the data warehouse (loading).

In the SQL SELECT command, the attributes to be retrieved are specified in the ____ clause.

SELECT

The SQL SELECT built-in function that adds the values of a specified set of attributes is ____.

SUM

Data redundancy

Same data stored unnecessarily at different places

Islands of information

Scattered locations storing the same basic data

File

Stores data, information, settings, or commands that are used in computation

Workgroup db

Supports < 50 users or specific department

Enterprise db

Supports more than 50 users across many departments

Multiuser db

Supports multiple users at a time

A value that is a foreign key in one relation of a database must be ____ another relation in the database.

The primary key of

Primary Key

Unique ID, cannot be NULL (entity integrity)

Functional dependency

Value of one attribute associated with single value of another attribute

In the SQL SELECT command, the search arguments that limit the rows involved in the query are specified in the ____ clause.

WHERE

Data is verifiable if

Yeilds consistent results

A single piece of data is _____ the business environment.

a fact about

The SQL CREATE TABLE command is capable of doing all of the following, EXCEPT ____. a. building indexes b. specifying which attributes are unique c. specifying which attributes serve as the primary key d. specifying referential integrity constraints e. specifying which attributes serve as foreign keys

a. building indexes

All of the following are basic principles of the database concept, EXCEPT _____. a. maintaining redundant data that does not cause data integrity problems b. the ability to store data in a non-redundant fashion c. the ability to store data representing entities involved in multiple relationships d. striving to achieve a high degree of data independence e. data integration

a. maintaining redundant data that does not cause data integrity problems

All of the following are SQL commands, EXCEPT ____. a. CREATE TABLE b. CREATE SELECT c. CREATE INDEX d. CREATE VIEW e. DROP TABLE

b. CREATE SELECT

Problems caused by two or more users trying to update the same data simultaneously fall primarily under the heading of _____.

concurrency control

When data structures can be modified without affecting the programs that use the data, we say that the environment is highly _____.

data independent

The SQL SELECT GROUP BY clause is designed to ____.

group together the rows of a table that have a common attribute value

An one-to-one unary relationship _____.

involves a single entity type

Which of the following is the unique identifier of an entity?

key

An associative entity is an alternate way of expressing a(n) _____.

many-to-many binary relationship

A many-to-many unary relationship allows an occurrence of one entity type to be associated with _____.

multiple occurrences of the same entity type

An one-to-many unary relationship allows an occurrence of the entity type on the "one side" of the relationship to be associated with _____.

multiple occurrences of the same entity type

A ternary relationship allows an occurrence of one entity type to be associated with _____.

multiple occurrences of two other entity types

The values of the primary key of a relation ____.

must be unique

Courses and their sections can best be described as a _____ relationship.

one-to-many binary

Relationship between students and the professors who have been their instructors is a _____ relationship.

one-to-many binary

Every professor reports to another professor who is the department chair. This is a _____ relationship.

one-to-many unary

Each student is paired with another student for the purpose of getting assignments and turning in work for the other if he is out of school for any reason. This is a _____ relationship.

one-to-one unary

Typing SQL SELECT commands in at a keyboard and sending them directly to the relational DBMS for processing is referred to as ____.

query mode

The SQL SELECT command is used to ____ a relational database.

retrieve data from

A university wants to keep track of which professor (1) taught which subject (2) to which student (3). This is a _____ relationship.

ternary

"Binary" in binary relationship

two entity types

All of the following are problems caused by redundant data, except _____. a. wasted disk space b. additional processing time for data updates c. wasted network transmission time d. potential data integrity problems e. the possibility of having what should be the same data value in two different files having different values.

wasted network transmission time