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Lecture 5

Databases and Information Systems

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What You Will Learn About

The potential uses of a database programThe basic components of a databaseThe differences between file management and

relational database programs Advanced database programs and applications

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What You Will Learn About

The basic qualities of a good databaseComponents and functions of an information systemFunctional divisions of an organizationMajor types of information systems used todayDatabases in retail organizations

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Database Concepts

Data is any unorganized text, graphics, sounds, or videos

A database is a collection of dataDatabase programs enable people to add,

sort, group, summarize, and print data Information is data that has been processed in

a meaningful and useful way

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The layers in a database are: Bits – The lowest layer made of 1s and 0s Characters – Letters, numbers, and symbols Fields – Areas that contain data identified by field names

(Examples: First Name; Address; City) Records – Contain a group of fields

Data files – Contain related records

Databases – The top layer made of one or more data files (Example: ABC Company Address Book Mailing list, Employee list, Vendor list)

The Levels of Data in a Database

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Data Type

Data usually consists of text, numbers, currency, and dates

Logical data – Only “yes” or “no” answers are allowed Objects – Non-textual data Binary large objects (BLOBs) – Very large objects Default value – Pre-defined values such as today’s date

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Data Type

One field in a record is identified as the key field or primary key

The key field must be a unique entry such as a social security number or student ID

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Types of Database Programs

File Management Programs:Create flat files containing one file or tableFiles can not be linked to other filesAre easy to use and customizeAre not as complex as database management systems

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Types of Database Programs

Database Management Systems (DBMS):Contain multiple files or tablesAre programs that enable data to be stored, modified, and

extracted from a databaseAre more difficult to learn than file management systems

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Relational Database Management Systems

Relational database management systems are the most widely used type of DBMS

Data in several files are related through the use of a common key field

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Data Warehousing and Data Mining

Data Warehousing:Supplements DBMSs by bringing together all data into one

huge databaseOrganizes management’s decision-making processUses a technique called drill-down to view performance

data of the entire company

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Data Warehousing and Data Mining

Data marts support one division of an organization rather than an entire firm

Data Mining: Is a data exploration technique Is used to find unknown patterns of data

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Client/Server Database Systems

Data server – Professionally administered program that runs on a local area network (LAN); it responds to requests for data

Client – A user-friendly program that accesses the server; users can add data, maintain records, perform queries, and generate reports

Clients request data using a query language called Structured Query Language (SQL)

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Client/Server Database Systems

Query Specially phrased question used to access specific information

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The Internet Connection: Going Public With Data

Web-based integration is the latest trend in database software

Information is stored in databases that are available through the Internet

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Advantages of Database Management Systems

Data integrity is the validity of the data.

Data validation defines acceptable input ranges for each field.

Types of data validation are:Alphabetic checkNumeric checkRange checkConsistency checkCompleteness check

Data independence refers to how data is stored so that it can be used with different types of application programs.

Avoidance of data redundancy refers to avoiding the repetition of data.

Data security is the unavailability of data to people who would misuse it.

Data is also protected from loss due to equipment failure.

Data maintenance refers to the procedures for adding, updating, and deleting records.

The areas of importance for building a quality database are:Data integrityData independenceAvoidance of data redundancyData securityData maintenance

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Information Systems: Tools for Global Competitiveness

An information system is designed to bring data, computers, procedures, and people together to manage information important to an organization’s mission

To be valuable, information must be:AccessibleAccurateCompleteEconomicalRelevant

Reliable Secure Simple Timely Verifiable

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Functional Divisions of an Organization

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Transaction Processing Systems (TPSs)

TPSs handle an organization’s accounting needsEarly TPSs used batch processing systemsOnline processing consists of entering transaction

data and viewing the results immediatelyTPSs enable managers to make operational

decisionsTPSs can produce summary and exception reports

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Management Information Systems (MISs)MISs are computer-based systems that support the

information needs of different levels of managementMISs help management make informed tactical

decisionsMISs work with transaction processing systemsMISs inform managers if their goals are being metDrawbacks of MISs:

Reports may contain unwanted information Information may not be available when needed Reams of printouts

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Decision Support Systems (DSSs)

DSSs enable managers to ask questions that can’t be answered by MIS reports

Online Analytical Processing (OLAP) enables managers to import up-to-the-minute reports from transaction databases

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Executive Information Systems (EISs)

EISs are also known as executive support systems (ESSs)

EISs support strategic decisions made by top level management that will affect the entire company

EISs filter critical information so that trends are apparent

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Strategic decisions

Tactical decisions

Operational decisions

Types of Decisions and Information Systems for Managers

Organizational Pyramid

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Knowledge Management Systems

Knowledge management systems are used to capture knowledge created by employees and make it available when needed

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Expert SystemsExpert systems are systems that deal with expert

knowledge in a particular areaExpert systems:

Help in making decisionsUse artificial intelligence principlesProvide technical support for customers

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Computers and Databases in the Retail Sector

Computers and databases are used for the checkout process and strategic purposes

At the checkout stand:Point of sale terminals are replacing the cash registerOptical scanners read the universal product code (UPC) label that identifies items, their costs, and any sale pricesCredit card authorization terminals are used to process credit card transactions by placing a call to a call center which provides authorization numbers

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Computers and Databases in the Retail Sector

At the checkout stand (continued):Check-screening systems read the check’s account

number, then compare it with delinquent accountsSignature capture systems capture a customer’s signature

on a pressure sensitive padPhoto checkout systems display a customer’s photo when

a credit card is used

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Lecture 5 Summary• Database software transforms data into information• Information is data that is organized to be meaningful and

useful• A database file is made of:

CharactersFieldsRecords

• File management programs work with one database file• DBMSs can work with two or more database files at a time• A good database system contains:

Data integrityData independenceData redundancy avoidance measuresData securityData maintenance procedures

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Lecture 5 Summary continued• A computer information system provides essential services to an

organization• Information systems include:

Transaction processing systems (TPS)Management information systems (MIS)Decision support systems (DSS)Executive information systems (EIS)Knowledge management systems (KMS)Expert systems (ES)

• Computers and databases provide an indispensable resource for the retail sector