ChapterChapter 11::Chapter Chapter 11::The Database EnvironmentThe Database Environment

Modern Database ManagementModern Database Management99thth EditionEdition99 EditionEdition

Jeffrey A. Hoffer, Mary B. Prescott, Jeffrey A. Hoffer, Mary B. Prescott, Heikki TopiHeikki Topi

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ObjectivesObjectivesDefinition of termsDefinition of termsExplain growth and importance of databasesExplain growth and importance of databasesp g pp g pName limitations of conventional file processingName limitations of conventional file processingIdentify five categories of databasesIdentify five categories of databasesIdentify five categories of databasesIdentify five categories of databasesExplain advantages of databasesExplain advantages of databases

f ff fIdentify costs and risks of databasesIdentify costs and risks of databasesList components of database environmentList components of database environmentDescribe evolution of database systemsDescribe evolution of database systems

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DefinitionsDefinitionsDatabase: organized collection of logically Database: organized collection of logically related datarelated dataData: stored representations of meaningful Data: stored representations of meaningful objects and eventsobjects and eventsjj

Structured: numbers, text, datesStructured: numbers, text, datesUnstructured: images, video, documentsUnstructured: images, video, documentsg , ,g , ,

Information: data processed to increase Information: data processed to increase knowledge in the person using the dataknowledge in the person using the dataknowledge in the person using the dataknowledge in the person using the dataMetadata: data that describes the properties and Metadata: data that describes the properties and context of user datacontext of user data

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context of user datacontext of user data

Figure 1-1a Data in context

Context helps users understand data

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Context helps users understand data

Figure 1-1b Summarized data

Graphical displays turn data into useful Graphical displays turn data into useful information that managers can use for

decision making and interpretation

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g p

Descriptions of the properties or characteristics of the Descriptions of the properties or characteristics of the data, including data types, field sizes, allowable

values, and data context

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Disadvantages of File ProcessingDisadvantages of File Processingg gg g

ProgramProgram--Data DependenceData DependenceProgramProgram Data DependenceData DependenceAll programs maintain metadata for each file they useAll programs maintain metadata for each file they use

Duplication of DataDuplication of DataDuplication of DataDuplication of DataDifferent systems/programs have separate copies of the same dataDifferent systems/programs have separate copies of the same data

Limited Data SharingLimited Data SharingLimited Data SharingLimited Data SharingNo centralized control of dataNo centralized control of data

Lengthy Development TimesLengthy Development TimesLengthy Development TimesLengthy Development TimesProgrammers must design their own file formatsProgrammers must design their own file formats

Excessive Program MaintenanceExcessive Program MaintenanceExcessive Program MaintenanceExcessive Program Maintenance8080% of information systems budget% of information systems budget

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Problems with Data DependencyProblems with Data DependencyProblems with Data DependencyProblems with Data DependencyEach application programmer must maintainEach application programmer must maintainEach application programmer must maintain Each application programmer must maintain his/her own datahis/her own dataEach application program needs to includeEach application program needs to includeEach application program needs to include Each application program needs to include code for the metadata of each filecode for the metadata of each fileEach application program must have its ownEach application program must have its ownEach application program must have its own Each application program must have its own processing routines for reading, inserting, processing routines for reading, inserting, updating and deleting dataupdating and deleting dataupdating, and deleting dataupdating, and deleting dataLack of coordination and central controlLack of coordination and central controlNonNon standard file formatsstandard file formatsNonNon--standard file formatsstandard file formats

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Duplicate Datap

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Problems with Data RedundancyProblems with Data Redundancy

Waste of space to have duplicate dataWaste of space to have duplicate datap pp pCauses more maintenance headachesCauses more maintenance headachesThe biggest problem: The biggest problem:

Data changes in one file could causeData changes in one file could causeData changes in one file could cause Data changes in one file could cause inconsistenciesinconsistenciesCompromises in Compromises in data integritydata integrity

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SOLUTION:SOLUTION:SOLUTION: SOLUTION: The DATABASE ApproachThe DATABASE Approachpppp

Central repository of shared dataCentral repository of shared datap yp yData is managed by a controlling Data is managed by a controlling

ttagentagentStored in a standardized, convenientStored in a standardized, convenientStored in a standardized, convenient Stored in a standardized, convenient formform

Requires a Database Management System (DBMS)

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Database Management SystemDatabase Management SystemA software system that is used to create, maintain, and provide controlled access to user databases

Order FilingSystemSystem

Invoicing Central databaseInvoicingSystem DBMS

Central database

Contains employee,order, inventory,

PayrollSystem

order, inventory, pricing, and

customer data

DBMS manages data resources like an operating system manages hardware resources

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DBMS manages data resources like an operating system manages hardware resources

Advantages of the Database ApproachAdvantages of the Database ApproachAdvantages of the Database ApproachAdvantages of the Database Approach

ProgramProgram--data independencedata independenceProgramProgram data independencedata independencePlanned data redundancyPlanned data redundancyImproved data consistencyImproved data consistencyImproved data consistencyImproved data consistencyImproved data sharingImproved data sharingIncreased application development productivityIncreased application development productivityIncreased application development productivityIncreased application development productivityEnforcement of standardsEnforcement of standardsImproved data qualityImproved data qualityImproved data qualityImproved data qualityImproved data accessibility and responsivenessImproved data accessibility and responsivenessReduced program maintenanceReduced program maintenanceReduced program maintenanceReduced program maintenanceImproved decision supportImproved decision support

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Costs and Risks of the Database Costs and Risks of the Database ApproachApproach

New, specialized personnelNew, specialized personnelI ll i d dI ll i d dInstallation and management cost and Installation and management cost and complexitycomplexityp yp yConversion costsConversion costsN d f li it b k dN d f li it b k dNeed for explicit backup and recoveryNeed for explicit backup and recoveryOrganizational conflictOrganizational conflictgg

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Elements of the Database ApproachElements of the Database Approach

Data modelsData modelsData models Data models Graphical system capturing nature and relationship of dataGraphical system capturing nature and relationship of dataEnterprise Data ModelEnterprise Data Model––highhigh--level entities and relationships for level entities and relationships for the organizationthe organizationthe organizationthe organizationProject Data ModelProject Data Model––more detailed view, matching data structure more detailed view, matching data structure in database or data warehouse in database or data warehouse

Relational DatabasesRelational DatabasesRelational DatabasesRelational DatabasesDatabase technology involving tables (relations) representing Database technology involving tables (relations) representing entities and primary/foreign keys representing relationshipsentities and primary/foreign keys representing relationships

Use of Internet TechnologyUse of Internet TechnologyUse of Internet TechnologyUse of Internet TechnologyNetworks and telecommunications, distributed databases, clientNetworks and telecommunications, distributed databases, client--server, and server, and 33--tier architecturestier architectures

D t b A li tiD t b A li tiDatabase ApplicationsDatabase ApplicationsApplication programs used to perform database activities Application programs used to perform database activities (create, read, update, and delete) for database users(create, read, update, and delete) for database users

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Figure 1-2 Comparison of enterprise and project level data models

Segment of an enterprise data model

Segment of a project-level data model

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One customer may place manymay place many orders, but each order is placed byorder is placed by a single customer

One-to-manyOne-to-many relationship

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One order has many order lines; each order line is

i t d ithassociated with a single order

One-to-many relationship

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One product can be in many order lines, each order line refersorder line refers to a single productp

One-to-many relationshiprelationship

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

Many-to-many relationship

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Figure 1-5 Components of the Database Environment

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Components of the Components of the bbDatabase EnvironmentDatabase Environment

CASE T lCASE T l tt id d ft i iid d ft i iCASE ToolsCASE Tools––computercomputer--aided software engineeringaided software engineeringRepositoryRepository––centralized storehouse of metadatacentralized storehouse of metadataDatabase Management System (DBMS)Database Management System (DBMS) ––softwaresoftwareDatabase Management System (DBMS) Database Management System (DBMS) ––software software for managing the databasefor managing the databaseDatabaseDatabase––storehouse of the datastorehouse of the dataApplication ProgramsApplication Programs––software using the datasoftware using the dataUser InterfaceUser Interface––text and graphical displays to userstext and graphical displays to usersD t /D t b Ad i i t tD t /D t b Ad i i t t llData/Database AdministratorsData/Database Administrators––personnel personnel responsible for maintaining the databaseresponsible for maintaining the databaseSystem DevelopersSystem Developers––personnel responsible forpersonnel responsible forSystem DevelopersSystem Developers personnel responsible for personnel responsible for designing databases and softwaredesigning databases and softwareEnd UsersEnd Users––people who use the applications and people who use the applications and d t bd t b

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databasesdatabases

The Range of Database ApplicationsThe Range of Database ApplicationsThe Range of Database ApplicationsThe Range of Database Applications

Personal databasesPersonal databasesW k d bW k d bWorkgroup databasesWorkgroup databasesDepartmental/divisional databasesDepartmental/divisional databasesDepartmental/divisional databasesDepartmental/divisional databasesEnterprise databaseEnterprise database

Enterprise resource planning (ERP) systemsEnterprise resource planning (ERP) systemsData warehousing implementationsData warehousing implementations

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Table 1-6 Summary of Database Applications

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Figure 1-7 Workgroup database with wireless local area networklocal area network

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Enterprise Database ApplicationsEnterprise Database ApplicationsEnterprise Database ApplicationsEnterprise Database Applications

Enterprise Resource Planning (ERP)Enterprise Resource Planning (ERP)I t t ll t i f tiI t t ll t i f tiIntegrate all enterprise functions Integrate all enterprise functions (manufacturing, finance, sales, marketing, (manufacturing, finance, sales, marketing, i t ti h )i t ti h )inventory, accounting, human resources)inventory, accounting, human resources)

Data WarehouseData WarehouseIntegrated decision support system derived Integrated decision support system derived from various operational databasesfrom various operational databasesfrom various operational databasesfrom various operational databases

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Figure 1-8 An enterprise data warehouse

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WebWeb--Enabled DatabasesEnabled DatabasesWebWeb Enabled DatabasesEnabled Databases

Web applications requiring databasesWeb applications requiring databasesC t l ti hi t (CRM)C t l ti hi t (CRM)Customer relationship management (CRM)Customer relationship management (CRM)BusinessBusiness--toto--consumer (Bconsumer (B22C)C)Electronic data interchange (EDI)Electronic data interchange (EDI)Private intranetsPrivate intranetsPrivate intranetsPrivate intranetsXMLXML--defined Web servicesdefined Web services

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WebWeb--Enabled Databases (cont )Enabled Databases (cont )WebWeb Enabled Databases (cont.)Enabled Databases (cont.)

Issues to considerIssues to considerWhi h t h l i t ?Whi h t h l i t ?Which technologies to use?Which technologies to use?Security/privacy protectionSecurity/privacy protectionManaging huge volumes of data from Internet Managing huge volumes of data from Internet transactionstransactionsMaintaining data qualityMaintaining data quality

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Figure 1-9 Evolution of database technologies

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