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CHAPTER 1:THE DATABASE ENVIRONMENT AND DEVELOPMENT PROCESSModern
Database Management11th Edition, International EditionJeffrey A.
Hoffer, V. Ramesh, Heikki Topi 2013 Pearson Education*
Chapter 1 2013 Pearson Education
OBJECTIVESDefine termsName limitations of conventional file
processingExplain advantages of databasesIdentify costs and risks
of databasesList components of database environmentIdentify
categories of database applicationsDescribe database system
development life cycleExplain prototyping and agile development
approachesExplain roles of individualsExplain the three-schema
architecture for databases*
Chapter 1 2013 Pearson Education
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 data*
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*Figure 1-1a Data in contextContext helps users understand
data*Chapter 1 2013 Pearson Education
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*Graphical displays turn data into useful information that
managers can use for decision making and interpretationFigure 1-1b
Summarized data*Chapter 1 2013 Pearson Education
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*Descriptions of the properties or characteristics of the data,
including data types, field sizes, allowable values, and data
context*Chapter 1 2013 Pearson Education
Chapter 1 2013 Pearson Education
DISADVANTAGES 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
budget*
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PROBLEMS 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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**Chapter 1 2013 Pearson Education
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PROBLEMS WITH DATA REDUNDANCYWaste of space to have duplicate
dataCauses more maintenance headachesThe biggest problem: Data
changes in one file could cause inconsistenciesCompromises in data
integrity*
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SOLUTION: THE DATABASE APPROACHCentral repository of shared
dataData is managed by a controlling agentStored in a standardized,
convenient form
*Requires a Database Management System (DBMS)
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DATABASE MANAGEMENT SYSTEM*DBMS 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 SystemDBMS
Central database
Contains employee,order, inventory, pricing, and customer
data
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ADVANTAGES 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
*
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COSTS AND RISKS OF THE DATABASE APPROACHNew, specialized
personnelInstallation and management cost and complexityConversion
costsNeed for explicit backup and recoveryOrganizational
conflict*
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ELEMENTS OF THE DATABASE APPROACHData models Graphical 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 EntitiesNoun form
describing a person, place, object, event, or conceptComposed of
attributesRelationshipsBetween entitiesUsually one-to-many (1:M) or
many-to-many (M:N)Relational DatabasesDatabase technology involving
tables (relations) representing entities and primary/foreign keys
representing relationships
*
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*Segment of an enterprise data modelSegment of a project-level
data modelFigure 1-3 Comparison of enterprise and project level
data models*Chapter 1 2013 Pearson Education
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*One customer may place many orders, but each order is placed by
a single customer One-to-many relationship*Chapter 1 2013 Pearson
Education
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*One order has many order lines; each order line is associated
with a single order One-to-many relationship*Chapter 1 2013 Pearson
Education
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*One product can be in many order lines, each order line refers
to a single product One-to-many relationship*Chapter 1 2013 Pearson
Education
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*Therefore, one order involves many products and one product is
involved in many orders
Many-to-many relationship*Chapter 1 2013 Pearson Education
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**Chapter 1 2013 Pearson Education
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*Figure 1-5 Components of the Database Environment
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COMPONENTS 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 databases*
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ENTERPRISE DATA MODELFirst step in the database development
processSpecifies scope and general contentOverall picture of
organizational data at high level of abstractionEntity-relationship
diagramDescriptions of entity typesRelationships between
entitiesBusiness rules*
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*FIGURE 1-6 Example business function-to-data entity
matrix*Chapter 1 2013 Pearson Education
Chapter 1 2013 Pearson Education
TWO APPROACHES TO DATABASE AND IS DEVELOPMENTSDLCSystem
Development Life CycleDetailed, well-planned development
processTime-consuming, but comprehensiveLong development
cyclePrototypingRapid application development (RAD)Cursory attempt
at conceptual data modelingDefine database during development of
initial prototypeRepeat implementation and maintenance activities
with new prototype versions
*
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SYSTEMS DEVELOPMENT LIFE CYCLE(SEE ALSO FIGURE 1-7) *
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SYSTEMS DEVELOPMENT LIFE CYCLE(SEE ALSO FIGURE 1-7)
(CONT.)*PlanningPurposepreliminary understandingDeliverablerequest
for study Database activity enterprise modeling and early
conceptual data modeling
Chapter 1 2013 Pearson Education
SYSTEMS DEVELOPMENT LIFE CYCLE(SEE ALSO FIGURE 1-7) (CONT.)
*AnalysisPurposethorough requirements analysis and
structuringDeliverablefunctional system specificationsDatabase
activitythorough and integrated conceptual data modeling
Chapter 1 2013 Pearson Education
SYSTEMS DEVELOPMENT LIFE CYCLE(SEE ALSO FIGURE 1-7) (CONT.)
*Logical DesignPurposeinformation requirements elicitation and
structureDeliverabledetailed design specificationsDatabase activity
logical database design (transactions, forms, displays, views, data
integrity and security)
Chapter 1 2013 Pearson Education
SYSTEMS DEVELOPMENT LIFE CYCLE(SEE ALSO FIGURE 1-7) (CONT.)
*Physical DesignPurposedevelop technology and organizational
specifications
Deliverableprogram/data structures, technology purchases,
organization redesignsDatabase activity physical database design
(define database to DBMS, physical data organization, database
processing programs)
Chapter 1 2013 Pearson Education
SYSTEMS DEVELOPMENT LIFE CYCLE(SEE ALSO FIGURE 1-7) (CONT.)
*ImplementationPurposeprogramming, testing, training, installation,
documenting
Deliverableoperational programs, documentation, training
materialsDatabase activity database implementation, including coded
programs, documentation, installation and conversion
Chapter 1 2013 Pearson Education
SYSTEMS DEVELOPMENT LIFE CYCLE(SEE ALSO FIGURE 1-7) (CONT.)
*MaintenancePurposemonitor, repair, enhance
Deliverableperiodic auditsDatabase activity database
maintenance, performance analysis and tuning, error corrections
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*Prototyping Database Methodology (Figure 1-8) *Chapter 1 2013
Pearson Education
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*Prototyping Database Methodology (Figure 1-8) (cont.)*Chapter 1
2013 Pearson Education
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*Prototyping Database Methodology (Figure 1-8) (cont.) *Chapter
1 2013 Pearson Education
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*Prototyping Database Methodology (Figure 1-8) (cont.)
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*Prototyping Database Methodology (Figure 1-8) (cont.)*Chapter 1
2013 Pearson Education
Chapter 1 2013 Pearson Education
DATABASE SCHEMAExternal SchemaUser ViewsSubsets of Conceptual
SchemaCan be determined from business-function/data entity
matricesDBA determines schema for different usersConceptual
SchemaE-R modelscovered in Chapters 2 and 3Internal Schema Logical
structurescovered in Chapter 4Physical structurescovered in Chapter
5
*
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*Different people have different views of the databasethese are
the external schemaThe internal schema is the underlying design and
implementationFigure 1-9 Three-schema architecture*Chapter 1 2013
Pearson Education
Chapter 1 2013 Pearson Education
MANAGING PROJECTSProjecta planned undertaking of related
activities to reach an objective that has a beginning and an
endInitiated and planned in planning stage of SDLCExecuted during
analysis, design, and implementationClosed at the end of
implementation
*
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MANAGING PROJECTS: PEOPLE INVOLVEDBusiness analystsSystems
analystsDatabase analysts and data modelersUsersProgrammersDatabase
architectsData administratorsProject managersOther technical
experts*
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EVOLUTION OF DATABASE SYSTEMSDriven by four main objectives:Need
for program-data independence reduced maintenanceDesire to manage
more complex data types and structuresEase of data access for less
technical personnelNeed for more powerful decision support
platforms
*
Chapter 1 2013 Pearson Education
*Figure 1-10a Evolution of database technologies
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*Figure 1-10b Database architectures
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*Figure 1-10b Database architectures (cont.)
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*Figure 1-10b Database architectures (cont.)
Chapter 1 2013 Pearson Education
THE RANGE OF DATABASE APPLICATIONSPersonal databasesTwo-tier and
N-tier Client/Server databasesEnterprise applicationsEnterprise
resource planning (ERP) systemsData warehousing
implementations*
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*Figure 1-11 Two-tier database with localarea network*Chapter 1
2013 Pearson Education
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*Figure 1-12 Three-tiered client/server database
architecture*Chapter 1 2013 Pearson Education
Chapter 1 2013 Pearson Education
ENTERPRISE 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 databases*
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*FIGURE 1-13 ComputerSystem for Pine ValleyFurniture
Company*Chapter 1 2013 Pearson Education
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*Copyright 2013 Pearson Education
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