Introduction to Databases

Chapter 1: Introducing Data and Data Management

Data

• Stream of raw, unorganized facts

• Single piece of data is single fact: – Refrigerator SSN 958304 manufactured

11/05/2006

• Information: Data organized into form people can understand or use

Databases• Ordered collections of related data

elements• Designed to meet organization’s

information needs• Designed to be shared by multiple

users• Help transform data into information

– For example, used to transform store cash register transactions into sales reports

Example: Airline Ticketing & Reservations Company

Example: Airline Ticketing & Reservations Company

Data Management

• Uses databases and database management software (DBMS)

• Allows organizations to:– Easily access data

– Handle greater quantities of data

– Share data

– Reduce data redundancy (unwanted duplicate data)

Data Sources• To understand what data is meaningful,

examine company’s core business and processes

• Processes: Series of tasks that accomplish specific goal

• Primary processes help fulfill core business• To carry out process, company needs

resources and assets, such as:– Buildings and equipment– People– Money– Information from relevant data sources

Example: Car Rentals

• Core business– Rent cars

• Primary processes– Processes to manage fleet and service

cars

Example: Car Rentals: Departmental Activities

Specific Data Sources

• Specific data important to company can be found in:– Current information held in business

documents

– Historic information

– Human sources: Employees at different levels can provide different types of information about data

Human Data Sources

Data Flows

• Part of data collection process includes understanding how data flows through organization

• Data: Similar to water, flowing from source to destination

• However, unlike river, data may have many destinations, or data consumers

Data Concerns

• Data accuracy

• Data security

• Data organization

• Data access

Data Accuracy• Involves ensuring accurate and

correct data• Inaccurate data:

– Employee mistakes, shortcuts, and biases– Outdated– Poorly designed formulas or algorithms

• Maintaining data accuracy includes:– Verifying data sources– Managing data entry and manipulation

Data Security

• Processes and procedures implemented with goal of keeping data safe

• Basic data security categories include:– Access security

– Physical security

Access Security• Involves controlling user and application

access to data, usually through one or more authentication methods

• To reduce data source’s vulnerability:– Reduce surface area (how exposed

database is to access and manipulation by consumer audience)

• As potential consumer audience increases, so do potential security concerns

Access Security

Physical Security• Involves protecting data against

physical corruption or loss • Three basic tasks :

– Protecting server • Secure server in locked room with limited

access

– Ensuring storage media• Use fault-tolerant disk system

– Duplicating data• Maintain duplicate of data on mirror image, or

make data backups

Data Organization

• Forces structure on data• Helps reduce amount of physical

space data requires• Helps minimize time required to

locate and retrieve data • Data standards: Help ensure that

right amount of data is entered in same way for every data object

Data Access

• Data queries retrieve data, insert new data, or manipulate existing data

• Before database setup, determine:– Who needs access to data

• User roles or responsibilities

– What level of access is needed • Full or limited access

– Type of access needed• Directly or indirect through separate

application

Summary• Data are raw facts that organizations

collect and transform into meaningful information

• Data and information are primary business resource

• Data management through databases help support business’s primary processes and core business

• Data management concerns include data accuracy, data security, data organization, and data access

Key Terms• Access security• Authentication

method• Consumer audience• Core business• Data• Data access• Data accuracy• Data consumer

• Data query• Data security• Database• Fault-tolerant disk

system• Information• Mirror image• Physical security• Surface area

Copyright NoticeCopyright 2008 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Requests for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information herein.