Information Systems and Databases

Question 1

Attribute

Answer 1

A defined property (or characteristic) of an entity in a database. Eg Entity = customer, attribute = name, address (ie fieldname)

Question 2

Centralised database

Answer 2

A centralised database has all its data residing in one place

Question 3

Composite key

Answer 3

A combination of two or more fields used to identify a record in the database.

Question 4

Database

Answer 4

An organised collection of related data, stored in a way that meaningful information can be extracted.

Question 5

Data dictionary

Answer 5

A list of field names containing information about how the data in each field is to be constructed

Question 6

Data independence

Answer 6

The property of a DMA that allows you to change the schema at one level without requiring a change at the next level.

Question 7

Data integrity

Answer 7

The accuracy, reliability and consistency of data. A well-designed database will enforce data integrity. An example: A use could accidentally try to enter a phone number in a date field.

Question 8

Data mining

Answer 8

An analysis process that discovers new unintended relationships amongst data.

Question 9

Data quality

Answer 9

Identifies how reliable and effective the data is in database; involves the accuracy of the data

Question 10

Data redundancy

Answer 10

Repeated data in a database.

Question 11

Data security

Answer 11

The process of protecting data from destructive forces and unwanted actions of unauthorised users

Question 12

Data validation

Answer 12

The process of checking the validity of data at the data entry stage

Question 13

Data warehouse

Answer 13

Electronic storage of a large amount of information, used as a method for collecting data from a range of sources. Used to provide meaningful business insights through mining of the data.

Question 14

DBMS

Answer 14

Database Management System is software designed to define, manipulate, retrieve and manage data.

Question 15

Distributed database

Answer 15

A database that consists of two or more file located at different sites on a computer network

Question 16

Entity

Answer 16

A specific thing about which a system (ie database) collects. An entity is represented as a table in a database, eg customer, car, book

Question 17

First normal form

Answer 17

Each table cell should contain a single value and each record should be unique

Question 18

Flat file system

Answer 18

A stand- alone table of data

Question 19

Foreign key

Answer 19

The primary key of another table, linked by a relationship, that must appear in all tables linked tables.

Question 20

Form

Answer 20

Database object used for data entry. A form is the user interface for filling a table.

Question 21

Hypermedia

Answer 21

Any media type, eg image, video, text, audio that allows interactivity, typically by touching a screen or clicking a mouse

Question 22

Key

Answer 22

A field in database table used to sort data

Question 23

Metadata

Answer 23

Information about data that provides a common ground for people working on a project at the same time

Question 24

Network database

Answer 24

A database model that allows multiple records to be linked to the same owner file.

Question 25

Normalising

Answer 25

The process of organising data in a database, eg creating tables and establishing relationships between those table according to rules designed to protect data and enforce data integrity and reduce data redundancy.

Question 26

OLAP (Online Analytical Processing)

Answer 26

A software tool that provides analysis of data stored in a database and is used in data mining

Question 27

OLTP (Online transaction processing)

Answer 27

Refers to a class of systems that facilitate and manage transaction-oriented applications, typically for data entry and retrieval transaction processing

Question 28

Organising

Answer 28

Arranging data into tables within a database.

Question 29

Primary key

Answer 29

An attribute that has a unique value, used to identify individual records, eg student number, ISBN of a book, rego plate of a car.

Question 30

QBE (query by example)

Answer 30

A visual method of query where the search criteria is entered into an empty record and the records meeting this criterion will be displayed

Question 31

Query language

Answer 31

A non-procedural language, designed to allow the database used to ask questions of the database

Question 32

Redundancy

Answer 32

Repeated data in a database

Question 33

Relational database

Answer 33

Multiple tables within a database that are linked by relationships and key fields

Question 34

Relationship

Answer 34

The way in which entities (field names) are related to one another – the primary key is used to link entities

Question 35

Schema

Answer 35

An organised plan of an entire database showing where the data is found (tables and fieldnames) and the logical relationships

Question 36

Second Normal form

Answer 36

A relation is in second normal form if it is 1st normal form AND every non key attribute is fully functionally dependent on the primary key.

Question 37

Single key

Answer 37

Any single attribute that uniquely identifies each record in a table

Question 38

SQL

Answer 38

Structured Query Language is the standard language used to manage data in a database

Question 39

Table

Answer 39

Displays information about an entity, eg customers, sales, products. A row in a table represents one record.

Question 40

Validation

Answer 40

Check of the data to see if it is reasonable and lies within a predefined set of values

Question 41

Verification

Answer 41

Check of the data source to see if it is correct