Database Systems

Question 1

ad hoc query

Answer 1

A “spur-of-the-moment” question.

Question 2

centralized database

Answer 2

A database located at a single site.

Question 3

data

Answer 3

Raw facts, that is, facts that have not yet been processed to reveal their meaning to the end user.

Question 4

data anomaly

Answer 4

A data abnormality that exists when inconsistent changes to a database have been made. For example, an employee moves, but the address change is corrected in only one file and not across all files in the database.

Question 5

data dependence

Answer 5

A data condition in which the data representation and manipulation are dependent on the physical data storage characteristics.

Question 6

data dictionary

Answer 6

A DBMS component that stores metadata—data about data. Thus, the data dictionary contains the data definition as well as its characteristics and relationships. A data dictionary may also include data that are external to the DBMS. Also known as an information resource dictionary. See also active data dictionary, metadata, and passive data dictionary.q

Question 7

data inconsistency

Answer 7

A condition in which different versions of the same data yield different (inconsistent) results.

Question 8

data independence

Answer 8

A condition that exists when data access is unaffected by changes in the physical data storage characteristics.

Question 9

data integrity

Answer 9

In a relational database, refers to a condition in which the data in the database is in compliance with all entity and referential integrity constraints.

Question 10

database management

Answer 10

A process that focuses on data collection, storage, and retrieval. Common data management functions include addition, deletion, modification, and listing.

Question 11

data redundency

Answer 11

A condition that exists when a data environment contains redundant (unnecessarily duplicated) data.

Question 12

data warehouse

Answer 12

Bill Inmon, the acknowledged “father of the data warehouse,” defines the term as “an integrated, subject-oriented, time-variant, nonvolatile collection of data that provides support for decision making.”

Question 13

database

Answer 13

A shared, integrated computer structure that houses a collection of related data. A database contains two types of data: end-user data (raw facts) and metadata. The metadata consist of data about data, that is, the data characteristics and relationships.

Question 14

database design

Answer 14

The process that yields the description of the database structure. The database design process determines the database components. Database design is the second phase of the database life cycle.

Question 15

database management system

Answer 15

Refers to the collection of programs that manages the database structure and controls access to the data stored in the database.

Question 16

database system

Answer 16

An organization of components that defines and regulates the collection, storage, management, and use of data in a database environment.

Question 17

desktop database

Answer 17

A single-user database that runs on a personal computer.

Question 18

distributed database

Answer 18

A logically related database that is stored over two or more physically independent sites.

Question 19

enterprise database

Answer 19

The overall company data representation, which provides support for present and expected future needs.

Question 20

field

Answer 20

A character or group of characters (alphabetic or numeric) that defines a characteristic of a person, place, or thing. For example, a person’s Social Security number, address, phone number, and bank balance all constitute fields.

Question 21

file

Answer 21

A named collection of related records.

Question 22

information

Answer 22

The result of processing raw data to reveal its meaning. Information consists of transformed data and facilitates decision making.

Question 23

islands of information

Answer 23

A term used in the old-style file system environment to refer to independent, often duplicated, and inconsistent data pools created and managed by different organizational departments.

Question 24

knowledge

Answer 24

The body of information and facts about a specific subject. Knowledge implies familiarity, awareness, and understanding of information as it applies to an environment. A key characteristic of knowledge is that “new” knowledge can be derived from “old” knowledge.

Question 25

logical data format

Answer 25

The way in which a human being views data.

Question 26

metadata

Answer 26

Data about data, that is, data concerning data characteristics and relationships. See also data dictionary.

Question 27

multi-user database

Answer 27

A database that supports multiple concurrent users.

Question 28

operational database

Answer 28

A database that is designed primarily to support a company’s day-to-day operations. Also known as a transactional database or production database.

Question 29

performance tuning

Answer 29

Activities that make a database perform more efficiently in terms of storage and access speed.

Question 30

physical data format

Answer 30

The way in which a computer “sees” (stores) data.

Question 31

production database

Answer 31

The main database designed to keep track of the day-to-day operations of a company. See also transactional database.

Question 32

query

Answer 32

A question or task asked by an end user of a database in the form of SQL code. A specific request for data manipulation issued by the end user or the application to the DBMS.

Question 33

query language

Answer 33

A nonprocedural language that is used by a DBMS to manipulate its data. An example of a query language is SQL.

Question 34

query result set

Answer 34

The collection of data rows that are returned by a query.

Question 35

record

Answer 35

A collection of related (logically connected) fields.

Question 36

single-user database

Answer 36

A database that supports only one user at a time.

Question 37

structural dependence

Answer 37

A data characteristic that exists when a change in the database schema affects data access, thus requiring changes in all access programs.

Question 38

structural independence

Answer 38

A data characteristic that exists when changes in the database schema do not affect data access.

Question 39

Structured Query Language

Answer 39

A powerful and flexible relational database language composed of commands that enable users to create database and table structures, perform various types of data manipulation and data administration, and query the database to extract useful information.

Question 40

transactional database

Answer 40

A database designed to keep track of the day-to-day transactions of an organization. See also production database.

Question 41

work-group database

Answer 41

A multiuser database that supports a relatively small number of users (usually fewer than 50) or that is used for a specific department in an organization.