The Database Environment

DefinitionsDatabase: organized collection of logically related dataData: stored representations of meaningful objects and eventsStructured: numbers, text, datesUnstructured: images, video, documentsInformation: data processed to increase knowledge in the person using the dataMetadata: data that describes the properties and context of user data6Chapter 1ObjectivesDefinition of termsExplain growth and importance of databasesName limitations of conventional file processingIdentify five categories of databasesExplain advantages of databasesIdentify costs and risks of databasesList components of database environmentDescribe evolution of database systems2Chapter 1Continentals StoryA little over a decade ago, Continental was in real trouble, ranking at the bottom of U.S. airlines in on-time performance, mishandled baggage, customer complaints, and overbooking.Continental had had 10 CEOsToday :one of the most respected global airlines has been named the Most Admired Global Airline on Fortune magazines list of Most Admired Global Companies annually since 2004. recognized as Best Airline Based in North America the airline with the Best Airline Finance Deal by the 2008 OAG Airline of the Year awards.Implementation of a real-time or active data warehouse supported the companys business strategy, dramatically improving customer service and operations, creating cost savings, and generating revenue.3Chapter 1Better optimization of airfares using mathematical programming models that are able to adjust the number of seats sold at a particular fare using real-time sales dataImprovement of customer relationship management focused on Continentals most profitable customersImmediate availability of customer profilesSupport for union negotiations, including analysis of pilot staffing that allows management and union negotiators to evaluate the appropriateness of work assignment decisionsDevelopment of fraud profiles to identify transactions that appear to fit one of over 100 fraud profiles4Chapter 1Database NowadaysUsed in every aspect of lifeRapid growthDatabase technology will even greater importanceStill lot workShortage in skill5Chapter 1

7Chapter 18Figure 1-1a Data in contextContext helps users understand data

Chapter 19Graphical displays turn data into useful information that managers can use for decision making and interpretation

Figure 1-1b Summarized dataChapter 110Descriptions of the properties or characteristics of the data, including data types, field sizes, allowable values, and data context

Chapter 1Disadvantages of File ProcessingProgram-Data DependenceAll programs maintain metadata for each file they useDuplication of DataDifferent systems/programs have separate copies of the same dataLimited Data SharingNo centralized control of dataLengthy Development TimesProgrammers must design their own file formatsExcessive Program Maintenance80% of information systems budget11Chapter 1File Processing System

12Chapter 1Problems with Data DependencyEach application programmer must maintain his/her own dataEach application program needs to include code for the metadata of each fileEach application program must have its own processing routines for reading, inserting, updating, and deleting dataLack of coordination and central controlNon-standard file formats

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Figure 1-3 Old file processing systems at Pine Valley Furniture CompanyDuplicate DataChapter 1Problems with Data RedundancyWaste of space to have duplicate dataCauses more maintenance headachesThe biggest problem: Data changes in one file could cause inconsistenciesCompromises in data integrity15Chapter 1SOLUTION: The DATABASE ApproachCentral repository of shared dataData is managed by a controlling agentStored in a standardized, convenient form

16Requires a Database Management System (DBMS)Chapter 1Database Approach FundamentalsData ModelsGraphical system capturing nature and relationship of dataEnterprise Data Modelhigh-level entities and relationships for the organizationProject Data Modelmore detailed view, matching data structure in database or data warehouse EntityPerson, place, object, event or a concept in user environment about which the organization wishes to maintain dataRelationshipA well structured database establishes the relationships between entities that exists in organizational data so that information can be retrieved.17Chapter 118

Segment of an Enterprise Data ModelSegment of a Project-Level Data ModelChapter 1Elements of the Database ApproachRelational DatabasesDatabase technology involving tables (relations) representing entities and primary/foreign keys representing relationshipsDatabase Management System (DBMS)A software system that is used to create, maintain dan provide controlled access to user database.

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One customer may place many orders, but each order is placed by a single customer One-to-many relationshipChapter 121

One order has many order lines; each order line is associated with a single order One-to-many relationshipChapter 122

One product can be in many order lines, each order line refers to a single product One-to-many relationshipChapter 123

Therefore, one order involves many products and one product is involved in many orders

Many-to-many relationshipChapter 1Database Management System24DBMS manages data resources like an operating system manages hardware resourcesA software system that is used to create, maintain, and provide controlled access to user databasesOrder Filing SystemInvoicing SystemPayroll SystemDBMSCentral database

Contains employee,order, inventory, pricing, and customer dataChapter 1Advantages of the Database ApproachProgram-data independencePlanned data redundancyImproved data consistencyImproved data sharingIncreased application development productivityEnforcement of standardsImproved data qualityImproved data accessibility and responsivenessReduced program maintenanceImproved decision support

25Chapter 1Costs and Risks of the Database ApproachNew, specialized personnelInstallation and management cost and complexityConversion costsNeed for explicit backup and recoveryOrganizational conflict26Chapter 127

Figure 1-4 Enterprise data model for Figure 1-3 segmentsChapter 128Figure 1-5 Components of the Database Environment

Chapter 1Components of the Database EnvironmentCASE Toolscomputer-aided software engineeringRepositorycentralized storehouse of metadataDatabase Management System (DBMS) software for managing the databaseDatabasestorehouse of the dataApplication Programssoftware using the dataUser Interfacetext and graphical displays to usersData/Database Administratorspersonnel responsible for maintaining the databaseSystem Developerspersonnel responsible for designing databases and softwareEnd Userspeople who use the applications and databases29Chapter 1The Range of Database ApplicationsPersonal databasesTwo Tier DatabasesMulti-tier databasesEnterprise DatabaseData Warehousing30Chapter 1

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Figure 1-6Typical data from a personal databaseChapter 133Figure 1-7 Workgroup database with wireless local area network

Chapter 134

Chapter 1Enterprise Database ApplicationsEnterprise Resource Planning (ERP)Integrate all enterprise functions (manufacturing, finance, sales, marketing, inventory, accounting, human resources)Data WarehouseIntegrated decision support system derived from various operational databases35Chapter 136Figure 1-8 An enterprise data warehouse

Chapter 1Evolution of DB Systems37

Chapter 138

Chapter 139

Chapter 140Chapter 141Chapter 1