Chapter 4: Relational Databases

Question 1

database

Answer 1

a set of interrelated, centrally coordinated data files that are stored with as little data redundancy as possible

Question 2

database management system (DBMS)

Answer 2

the program that manages and controls the data and the interfaces between the data and the application programs that use the data stored in the database

Question 3

database system

Answer 3

the database, the DBMS, and the application programs that access the database through the DBMS

Question 4

database administrator

Answer 4

the person responsible for coordinating, controlling, and managing the database

Question 5

data warehouse

Answer 5

very large databases containing detailed and summarized data for a number of years that are used for analysis rather than transaction processing

Question 6

business intelligence

Answer 6

analyzing large amounts of data for strategic decision making

Question 7

online analytical processing (OLAP)

Answer 7

using queries to investigate hypothesized relationships among data

Question 8

data mining

Answer 8

using sophisticated statistical analysis to “discover” unhypothesized relationships in the data

Question 9

record layout

Answer 9

document that shows the items storied in a file, including the order and length of the data fields and the type of the data stored

Question 10

logical view

Answer 10

how people conceptually organize, view, and understand the relationships among data items

Question 11

physical view

Answer 11

the way data are physically arranged and stored in the computer system

Question 12

schema

Answer 12

a description of the data elements in a database, the relationships among them, and the logical model used to organize and describe the data

Question 13

conceptual-level schema

Answer 13

the organization-wide view of the entire database that lists all data elements and the relationships between them

Question 14

external-level schema

Answer 14

an individual user’s view of portions of a database; also called a subschema

Question 15

subschema

Answer 15

a subset of the schema; the way the user defines the data and the data relationships

Question 16

internal-level schema

Answer 16

a low-level view of the entire database describing how the data are actually stored and accessed

Question 17

data dictionary

Answer 17

information about the structure of the database, including a description of each data element

Question 18

data definition language (DDL)

Answer 18

DMBS language that builds the data dictionary, creates the database, describes logical views, and specifies record or field security constraints

Question 19

data manipulation language (DML)

Answer 19

DBMS language that changes database content, including data element creations, updates, insertions, and deletions

Question 20

data query language (DQL)

Answer 20

high-level, English-like DBMS language that contains powerful, easy-to-use commands that enable users to retrieve, sort, order, and display data

Question 21

report writer

Answer 21

DBMS language that simplifies report creation

Question 22

data model

Answer 22

an abstract representation of database contents

Question 23

relational data model

Answer 23

a two-dimensional table representation of data; each row represents a unique entity (record) and each column is a field where record attributes are stored

Question 24

tuple

Answer 24

a row in a table that contains data about a specific item in a database table

Question 25

primary key

Answer 25

database attribute, or combination of attributes, that uniquely identifies each row in a table

Question 26

foreign key

Answer 26

an attribute in a table that is also a primary key in another table; used to link the two tables

Question 27

update anomaly

Answer 27

improper database organization where a non-primary key item is stored multiple times; updating the item in one location and not the others causes data inconsistencies

Question 28

insert anomaly

Answer 28

improper database organization that results in the inability to add records to a database

Question 29

delete anomaly

Answer 29

improper organization of a database that results in the loss of all information about an entity when a row is deleted

Question 30

relational database

Answer 30

a database built using the relational data model

Question 31

entity integrity rule

Answer 31

a nonnull primary key ensures that every row in a table represents something and that it can be identified

Question 32

referential integrity rule

Answer 32

foreign keys which link rows in one table to rows in another table must have values that correspond to the value of a primary key in another table

Question 33

normalization

Answer 33

following relational database creation rules to design a relational database that is free from delete, insert, and update anomalies

Question 34

semantic data modeling

Answer 34

using knowledge of business processes and information needs to create a diagram that shows what to include in a fully normalized database (in 3NF)