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Computers Are Your Future. Chapter 4 Databases and Information Systems. Database Concepts. Data is any unorganized text, graphics, sounds, or videos. A database is a collection of data. Database programs enable people to add, sort, group, summarize, and print data.
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Computers Are Your Future Chapter 4 Databases and Information Systems
Database Concepts • Data is any unorganized text, graphics, sounds, or videos. • A database is a collection of data. • Database programs enable people to add, sort, group, summarize, and print data. • Information is data that has been processed in a meaningful and useful way.
The Levels of Data in a Database 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
The Levels of Data in a Database (Continued) These levels also include: • 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)
Data Type • Data usually consists of text, numbers, currency, and dates • Logical data– Only “yes” or “no” answers are allowed • Memos – large units of text • Objects– Non-textual data • Binary large objects (BLOBs) – Very large objects • Default value– Pre-defined values such as today’s date
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.
Types of Database Programs File Management Programs: • Create flat files containing one file or table • Files can not be linked to other files • Are easy to use and customize • Are not as complex as database management systems
Types of Database Programs Database Management Systems (DBMS) • Contain multiple files or tables • Are programs that enable data to be stored, modified, and extracted from a database • Are more difficult to learn than file management systems
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.
Data Warehousing and Data Mining Data Warehousing: • Supplements DBMSs by bringing together all data into one huge database • Organizes management’s decision-making process • Uses a technique called drill-down to view performance data of the entire company
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
Client/Server Database Systems Query: • Specially phrased question used to access specific information
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.
Advantages of Database Management Systems The areas of importance for building a quality database are: • Data integrity • Data independence • Avoidance of data redundancy • Data security • Data maintenance
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 check • Numeric check • Range check • Consistency check • Completeness check • Data securitymakes sure data are not accessible to unauthorized users. • Data is also protected from loss due to equipment failure.
Advantages of Database Management Systems • Data independence refers to how data is stored so that it can be used with different types of application programs. It also refers to the separation of the data in a database to control forms and reports. • Data maintenance refers to the procedures for adding, updating, and deleting records. • Avoidance of data redundancy refers to avoiding the repetition of data.
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.
Information Systems: Tools for Global Competitiveness • To be valuable, information must be: • Accessible • Accurate • Complete • Economical • Relevant *Definitions of each can be found on page 109, Figure 4.13 • Reliable • Secure • Simple • Timely • Verifiable
Transaction Processing System (TPS) • A TPS handles an organization’s accounting needs, including purchasing, sales & payroll. • Early TPSs used batch processing. • Online processing consists of entering transaction data and viewing the results immediately. • TPSs enable managers to make operational decisions. • TPSs can produce summary and exception reports.
Management Information System (MIS) • An MIS is a computer-based system that supports the information needs of different levels of management. • MISs help managers make informed tactical decisions. • MISs work with transaction processing systems. • MISs create reports that tell managers if their goals are being met. • Drawbacks of MISs: • Reports may contain unwanted information. • Information may not be available when needed. • Reams of printouts are often produced.
Decision Support System (DSS) • A DSS enables a manager to retrieve information that can’t be supplied by fixed and predetermined MIS reports. • Online Analytical Processing (OLAP) enables managers to import up-to-the-minute reports from transaction databases.
Executive Information System (EIS) • An EIS is also known as an executive support system (ESS). • EISs support strategic decisions made by top-level management that will affect the entire company. • EISs filter critical information so that trends are apparent.
Knowledge Management Systems • Knowledge management systems are used to capture knowledge created by employees and make it available when needed.
Expert Systems • Expert systems aresystems that deal with expert knowledge in a particular area. • Expert systems: • Help in making decisions • Use artificial intelligence principles • Provide technical support for customers
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 register. • Optical scanners read the universal product code (UPC) label that identifies items, their costs, and any sale prices.
Computers and Databases in the Retail Sector • At the checkout stand (continued): • Credit card authorization terminals are used to process credit card transactions by placing a call to a call center, which provides authorization numbers. • Check-screening systems read the check’s account number, then compare it with delinquent accounts. • Signature capture systems capture a customer’s signature on a pressure-sensitive pad. • Photo checkout systems display a customer’s photo when a credit card is used.