case studies

Question 1

ACID

Answer 1

Atomicity, Consistency, Isolation, Durability. Properties of a database that help guarantee data integrity.

Question 2

Adobe Flash Player

Answer 2

A web browser plugin which allows a variety of multimedia and interactive content to be included in web pages.

Question 3

Centralised database

Answer 3

A database in which all data is stored in a single central location.

Question 4

Distributed database

Answer 4

A database in which data is stored on multiple computers in separate physical locations. Various techniques are used to synchronise the data to prevent data integrity problems.

Question 5

Client-side software

Answer 5

In a web environment, refers to software that runs in the user’s browser rather than on the web server.

Question 6

Concurrency

Answer 6

Methods used to ensure multiple (concurrent) operations can be performed on a database without causing data integrity problems. Related to ACID and record locking.

Question 7

Customer relationship management (CRM) system

Answer 7

A computerised system for managing an organisation’s customer, sales, and marketing information. This might also include customer sales and technical support.

Question 8

Plug-ins

Answer 8

Software added to web browsers to extend their functionality.

Question 9

Record locking

Answer 9

Technique used in databases to prevent a record being accessed by more than one user at a time. This prevents data integrity problems (such as a change by one user while another is reading it).

Question 10

Smartphone

Answer 10

Mobile phone with capabilities typically including Internet access and a camera.

Question 11

Tablet device

Answer 11

Portable device, often with a touch screen.

Question 12

Atomicity

Answer 12

Part of ACID. A way of ensuring that database transactions either happen in their entirety, or not at all. For example, a payment from A to B must have money subtracted from person A and credited to person B. Atomicity means either both transactions occur, or neither do.

Question 13

Consistency

Answer 13

Part of ACID. Ensures that data in a database is always in a consistent state , i.e. that it follows all data validation rules. (Note that this is not the same as being correct).

Question 14

Isolation

Answer 14

Part of ACID. Ensures that one database transaction cannot unintentionally affect another. For example, two transactions to alter the same record cannot run at the same time.

Question 15

Durability

Answer 15

Part of ACID. Durability means that once a transaction has occurred, it must ‘stay occurred’, even if the power is lost or the hard disk crashes or there is some other disaster. This typically records a record of all transaction (a transaction log) to be kept.

Question 16

QR code

Answer 16

Quick Response Code. A type of 2D bar code that can store more data than a regular UPC bar code.

Question 17

Mail merge

Answer 17

The process of automatically customising a standard letter with individual names and addresses from a database.

Question 18

Unicode

Answer 18

Encoding system to store text, with support for multiple languages and alphabets, and thousands of characters. Compare ASCII.

Question 19

CMS

Answer 19

Content Management System. Software which allows management of a web site without web design skills. Content is stored in a database and published in different ways, such as on a web site, in a printed booklet, or in different languages. Sometimes called a WebCMS.

Question 20

Virtual Private Network

Answer 20

Allows a secure private connection over a public network, using an encrypted ‘tunnel’. For example, a remote computer can securely connect to a LAN, as though it were physically connected.

Question 21

Comma Separated Values

Answer 21

File format for transferring data, which stores fields and records in a plain text file, separated by commas. See also TSV (Tab Separated Values).