Computers Are Your Future Twelfth Editionjianhua/IIT... · 2016-08-12 · • Accounts payable,...

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Computers Are Your Future Twelfth Edition

Chapter 12: Databases and Information Systems

Databases and Information Systems

Objectives • Describe the basic components of a

database. • Describe the qualities of a good

database. • Distinguish between file management

programs and relational database management systems, and explain the advantages and disadvantages of each.

Objectives • Differentiate between advanced database

programs and applications, such as data warehouses, data mining, client/server database systems, and Web-database integration.

• List the components and main functions of an information system.

Objectives • Recognize the functional divisions and

business units of an organization. • List the major types of information

systems used in today’s organizations. • Describe how the retail sector is taking

advantage of computer databases to increase sales and gain a competitive edge.

Hierarchy(Levels) of Data Storage

• Database oFiles (Tables)

•Records (Rows) oFields (Columns)

•Characters (Types)(Bytes) oBits

The Levels of Data in a Database

• Database units (con’t.) o Database

• One or more related data files/tables o Data file (table)

• Collection of related records (rows)

• Database units (con’t.) o Record

• Includes a group of related fields • Contained in tables or data files • Has a primary key—unique identifier for each

record o Field

• Single unit of relative information • Has a field name—identifies content • Content is data type—includes items as Text,

Number, Currency, Date/Time

• Database units o Character (Byte)

• A letter, number, or symbol • Made of bytes—groups of 8 bits • Smallest useable unit of data

o Bit • Smallest unit of data stored by a computer • Contains either a 1 or a 0

• Database oOrganized collection of related data so it is

easy to: • Access • Manage • Update • Group • Summarize

Advantages of Database Management Systems

• Data integrity o Data is valid

• Data validation o Techniques used to

help prevent errors

• Data independence o Separate from applications o Changes do not require changes in structure of

forms, reports, or programs accessing databases

• Avoiding data redundancy o Enter data only once o Multiple entries of the same data—a sign of a poorly

developed system

• Data security o Prevents contents from being accessed by

unauthorized users (e.g., medical records, financial data)

o Audit trail—report of who accesses which data

• Data maintenance o Required for proper care and protection o Add records o Modify records o Delete records

Types of Database Programs

Database Programs • Software used to create databases

o File management program • Generates a flat file, meaning that there is no

relationship with fields in other files o Database management systems (DBMS’s)

• Manage multiple tables or files

• File management systems o Useful for personal and small business needs o Used to develop a simple computerized system for

information storage and retrieval o Inexpensive and easy to use o Unable to link to data stored in other files

• DBMS (Database management systems) o Connects several files or tables o Manages, accesses, stores, and edits data o Available in a variety of forms o Able to present information in reports and other

formats

Popular DBMS software

• DBMS classifications o Flat o Relational o Object oriented o Multidimensional

• RDBMS (Relational database management systems) o Most widely used class of DBMS o Primary key field used as index to locate records o Queries can be done through SQL o Data dictionary lists all tables in database o Compared to file management program, RDBMS is:

• More expensive • More difficult to learn • Better at controlling data redundancy • Better at preventing potential data errors

• Microsoft Access

• ODBMS (Object-oriented database management systems) o Suits media applications o Data represented as objects o Incorporate sound, video, text, and graphics o Well suited for applications such as:

• Financial portfolio risk analysis • Design and manufacturing systems • Hospital patient record systems

• Multidimensional databases o Depicted as a data cube o Dimensions typically

categories (i.e., time, products, sales, customers, budget, and markets)

o Choice for online analytical processing (OLAP)

• Data warehouses o Central location capable of storing all corporate

information o Data available for analysis o Helps executives make decisions

• Use drill-down method (start with summary level and move down) to focus on specific data

o Data marts similar but support a department or division

• Data mining o Explores and analyzes data o Determines data patterns

helpful for making decisions o Managers better understand

customers and market o Can help predict future

trends o Variation is Web mining

• Client/server database systems o Use database server software—responds to remote

users’ requests for information o Use database client software—provides an interface

with the user o Use queries to request information from the

database server • Examples: ATMs and online banking

• Web–database integration • Taking database information and making it accessible

via the Internet o Google, Yahoo!, Wikipedia

• Cloud computing database • Amazon SimpleDB • Google AppEngine Datastore • Microsoft SQL Data Services

Information Systems: Tools for Global Competitiveness

• Information systems o Integrate:

• People • Hardware • Software • Data • Procedures

• Information systems (con’t.) o Perform many functions:

• Accepts input (data) • Processes data into information • Stores data • Disseminates information throughout organization

• Reduce information overload o Route to appropriate users o Summarize o Provide information to selected people with specific

needs o Eliminate unnecessary information

• Functional divisions o Manage core functions

of an organization

Information Systems: Tools for Global Competiveness

• Typical functional divisions o Accounting

• Accounts payable, accounts receivable, cost accounting, sales information, accounting reports

• May use spreadsheets on a client/server network o Finance

• Forecasting, budgeting, cash management, budget analysis, financial reports

• Spreadsheets o Marketing and sales

• Maintaining public image and generating sales • Spreadsheets, Databases

• Typical functional divisions (con’t) o Human Resources

• Tracks employees • Databases

o Production/operation • Plans and controls processes that produce goods and

services • Mainframe systems

o Information Systems • System of people, data records, hardware and

software that process data and information

• Business units: Division of company, product line or group independent of other business units o Use of information systems:

• Analyze markets • Provide analysis and summary of market

information • Review and adjust strategies • Influence competition

Information Systems in Organizations: A Survey

• Transaction processing systems o Handle day-to-day accounting needs o Keeps record of every transaction involving money o Save money by automating routine recordkeeping o Batch online processing

• Management information systems o Provide information needed to make decisions o Generate predefined reports

• Decision support systems o Produce reports more specific than management

information system reports o Enable managers to create simulations

• OLAP (online analytical processing)

• Executive information systems o Help top-level managers make strategic decisions o Filter critical information to show trends

• Knowledge management systems o Use information from books and experienced

individuals to assist decision making

• Expert systems o Rely on detailed and in-depth knowledge of experts

in a specific field o Use knowledge base to generate answers

• Retail sector o Computers and databases not

only used for traditional applications

• Point-of-sale (POS) o Credit card authorization o Inventory system o Check-screening system o Signature capture system o Photo checkout system o Marketing devices

Summary • A database is a collection of data stored

in an organized way. The units of a database are: table or data file, records, field, and bit.

• A good database ensures data integrity, promotes data independence, avoids data redundancy, ensures data security, and provides procedures for data maintenance.

Summary • File management programs, which work

with a single flat file, are easy to use and inexpensive. A database management system works with two or more data files that can be related by common fields.

• Data warehouses bring data together from many smaller databases into one massive database. Data mining and Web mining explore data to discover unknown patterns.

Summary • Client-server database systems and Web–

database integration are examples of Database management systems (DBMS).

• An information system includes data, hardware, software, people, and procedures.

• Functional divisions of an organization include: accounting, finance, marketing and sales, human resources, production/ operations, and information systems.

Summary • Information systems include: transaction

processing systems, management information systems, decision support systems, executive information system, knowledge management systems, and expert systems.

• The retail sector’s use of POS terminals, when linked with inventory databases and other systems such as check-screening systems, provides businesses with the ability to perform many business tasks effectively.

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Computers Are Your Future Twelfth Editionjianhua/IIT... · 2016-08-12 · • Accounts payable,...

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