Chapter 1 Introduction to Database Management. McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies,...
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Transcript of Chapter 1 Introduction to Database Management. McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies,...
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Welcome! Welcome!
Database technology: crucial to the operation and management of modern organizations
Major transformation in computing skillsSignificant time commitmentExciting journey ahead
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Book GoalsBook Goals
First course in database managementPractical textbook
– Fundamentals of relational databases– Data modeling and normalization– Database application development– Database administration and database
processing environmentsDetailed material
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Outline Outline
Database characteristicsDBMS featuresArchitecturesOrganizational roles
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Initial VocabularyInitial Vocabulary
Data: raw facts about things and eventsInformation: transformed data that has
value for decision makingEssential to organize data for retrieval and
maintenance
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Database CharacteristicsDatabase Characteristics
Persistent
Inter-related
Shared
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
University DatabaseUniversity Database
University Database
Registration
GradeRecording
FacultyAssignment
CourseScheduling
Entities: students, faculty, courses, offerings, enrollmentsRelationships: faculty teach offerings, students enroll in offerings, offerings made of courses, ...
Water Utility DatabaseWater Utility Database
Billing
MeterReading
PaymentProcessing
Service Start/Stop
Entities :customers, meters, bills,payments, meter readingsRelationships :bills sent to customers,customers make payments,customers use meters, ...
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Database Management System Database Management System (DBMS)(DBMS)Collection of components that support data
acquisition, dissemination, storage, maintenance, retrieval, and formatting
Enterprise DBMSsDesktop DBMSsEmbedded DBMSsMajor part of information technology
infrastructure
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Database DefinitionDatabase Definition
Define database before usingTables and relationshipsSQL CREATE TABLE statementGraphical tools
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
University DatabaseUniversity Database
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
University Database (ERD)University Database (ERD)
StdSSNStdClassStdMajorStdGPA
StudentOfferNoOffLocationOffTime
Offering
EnrGrade
Enrollment
Registers
Accepts
CourseNoCrsDescCrsUnits
Course
FacSSNFacSalaryFacRankFacHireDate
Faculty
Has
Teaches
Supervises
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Nonprocedural AccessNonprocedural Access
Query: request for data to answer a question
Indicate what parts of database to retrieve not the procedural details
Improve productivity and improve accessibility
SQL SELECT statement and graphical tools
Loop
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Graphical Tool for Graphical Tool for Nonprocedural AccessNonprocedural Access
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Application DevelopmentApplication Development
Form: formatted document for data entry and display
Report: formatted document for displayUse nonprocedural access to specify data
requirements of forms and reports
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Sample Data Entry FormSample Data Entry Form
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Sample ReportSample Report
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Procedural Language InterfaceProcedural Language Interface
Combine procedural language with nonprocedural access
Why– Batch processing– Customization and automation– Performance improvement
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Transaction ProcessingTransaction Processing
Transaction: unit of work that should be reliably processed
Control simultaneous usersRecover from failures
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Database Technology Database Technology EvolutionEvolution
Era Generation Orientation Major Features
1960s 1st Generation File File structures and proprietary program interfaces
1970s 2nd Generation Network Navigation
Networks and hierarchies of related records, standard program interfaces
1980s 3rd Generation Relational Non-procedural languages, optimization, transaction processing
1990s 4th Generation Object Multi-media, active, distributed processing, more powerful operators
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
DBMS MarketplaceDBMS Marketplace
Enterprise DBMS– Oracle: dominates in Unix; strong in Windows– SQL Server: strong in Windows– Informix: significant Unix marketshare– DB2: strong in mainframe environment
Desktop DBMS– Access: dominates– FoxPro, Paradox, Approach, FileMaker Pro
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Data IndependenceData Independence
Software maintenance is a large part (50%) of information system budgets
Reduce impact of changes by separating database description from applications
Change database definition with minimal effect on applications that use the database
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Three Schema ArchitectureThree Schema Architecture
View 1 View 2 View n
ConceptualSchema
InternalSchema
ExternalLevel
ConceptualLevel
InternalLevel
External toConceptualMappings
Conceptualto InternalMappings
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Differences among LevelsDifferences among Levels
External– FacultyAssignmentFormView: data required
for the form in Slide 16 (Figure 1.9)– FacultyWorkLoadReportView: data required
for the report in Slide 17 (Figure 1.10) Conceptual: tables in Slide 11Internal
– Files needed to store the tables– Extra files to improve performance
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Client-Server ArchitectureClient-Server Architecture
Database
Database
a) Client, server, anddatabase on thesame computer
b) Mulitple clients and 1 serveron different computers
c) Multiple servers and databases on different computers
Client
Server
Client Server
Client Server Server
DatabaseDatabase
Client
Client
Client
Client
Client
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Organizational RolesOrganizational Roles
Indirec t Param etr ic Pow er
F unctiona l User
T echnica l Non T echnica l
D BA A na lys t/Program m er M anagem ent
Inform ation S ys tem s
Spec ia l iza tion
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Database SpecialistsDatabase Specialists
Database administrator (DBA)– More technical– DBMS specific skills
Data administrator– Less technical– Planning role
McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved.
SummarySummary
Databases and database technology vital to modern organizations
Database technology supports daily operations and decision making
Nonprocedural access is a crucial featureMany opportunities to work with databases