Upload
reynallie-bebb-ue-bagsic
View
223
Download
0
Embed Size (px)
Citation preview
8/13/2019 Chapter+1+ +the+Database+Environment
1/30
Chapter 1The Database Environment
Modern Database Management8 th Edition
Jeffrey A. Hoffer, Mary B. Prescott,Fred R. McFadden
8/13/2019 Chapter+1+ +the+Database+Environment
2/30
Chapter 1 2007 by Prentice Hall 2
ObjectivesDefinition 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 systems
8/13/2019 Chapter+1+ +the+Database+Environment
3/30
Chapter 1 2007 by Prentice Hall 3
DefinitionsDatabase: organized collection of logicallyrelated dataData: stored representations of meaningfulobjects and events
Structured: numbers, text, datesUnstructured: images, video, documents
Information: data processed to increaseknowledge in the person using the data
Metadata: data that describes the properties andcontext of user data
8/13/2019 Chapter+1+ +the+Database+Environment
4/30
Chapter 1 2007 by Prentice Hall 4
Figure 1-1a Data in context
Context helps users understand data
8/13/2019 Chapter+1+ +the+Database+Environment
5/30
Chapter 1 2007 by Prentice Hall 5
Graphical displays turn data into usefulinformation that managers can use for
decision making and interpretation
Figure 1-1b Summarized data
8/13/2019 Chapter+1+ +the+Database+Environment
6/30
Chapter 1 2007 by Prentice Hall 6
Descriptions of the properties or characteristics of thedata, including data types, field sizes, allowable
values, and data context
8/13/2019 Chapter+1+ +the+Database+Environment
7/30
Chapter 1 2007 by Prentice Hall 7
Disadvantages of File Processing
Program-Data Dependence All programs maintain metadata for each file they use
Duplication of DataDifferent systems/programs have separate copies of the same data
Limited Data SharingNo centralized control of data
Lengthy Development Times
Programmers must design their own file formatsExcessive Program Maintenance
80% of information systems budget
8/13/2019 Chapter+1+ +the+Database+Environment
8/30
Chapter 1 2007 by Prentice Hall 8
Problems with Data DependencyEach application programmer must maintainhis/her own dataEach application program needs to includecode for the metadata of each fileEach application program must have its ownprocessing routines for reading, inserting,updating, and deleting data
Lack of coordination and central controlNon-standard file formats
8/13/2019 Chapter+1+ +the+Database+Environment
9/30
Chapter 1 2007 by Prentice Hall 9
Figure 1-3 Old file processing systems at Pine ValleyFurniture Company
Duplicate Data
8/13/2019 Chapter+1+ +the+Database+Environment
10/30
Chapter 1 2007 by Prentice Hall 10
Problems with Data Redundancy
Waste of space to have duplicate data
Causes more maintenance headachesThe biggest problem:
Data changes in one file could cause
inconsistenciesCompromises in data integrity
8/13/2019 Chapter+1+ +the+Database+Environment
11/30
Chapter 1 2007 by Prentice Hall 11
SOLUTION:
The DATABASE ApproachCentral repository of shared data
Data is managed by a controllingagentStored in a standardized, convenient
formRequires a Database Management System (DBMS)
8/13/2019 Chapter+1+ +the+Database+Environment
12/30
Chapter 1 2007 by Prentice Hall 12
Database Management System
DBMS manages data resources like an operating system manages hardware resources
A software system that is used to create, maintain, and providecontrolled access to user databases
Order FilingSystem
InvoicingSystem
PayrollSystem
DBMSCentral database
Contains employee,order, inventory,
pricing, and
customer data
8/13/2019 Chapter+1+ +the+Database+Environment
13/30
Chapter 1 2007 by Prentice Hall 13
Advantages of the Database Approach
Program-data independencePlanned data redundancyImproved data consistencyImproved data sharingIncreased application development productivityEnforcement of standardsImproved data qualityImproved data accessibility and responsivenessReduced program maintenanceImproved decision support
8/13/2019 Chapter+1+ +the+Database+Environment
14/30
Chapter 1 2007 by Prentice Hall 14
Costs and Risks of the Database Approach
New, specialized personnelInstallation and management cost and
complexityConversion costsNeed for explicit backup and recoveryOrganizational conflict
8/13/2019 Chapter+1+ +the+Database+Environment
15/30
Chapter 1 2007 by Prentice Hall 15
Elements of the Database Approach
Data modelsGraphical system capturing nature and relationship of dataEnterprise Data Model high-level entities and relationships forthe organizationProject Data Model more detailed view, matching data structurein database or data warehouse
Relational DatabasesDatabase technology involving tables (relations) representingentities and primary/foreign keys representing relationships
Use of Internet TechnologyNetworks and telecommunications, distributed databases, client-server, and 3-tier architectures
Database Applications Application programs used to perform database activities(create, read, update, and delete) for database users
8/13/2019 Chapter+1+ +the+Database+Environment
16/30
Chapter 1 2007 by Prentice Hall 16
Segment of an Enterprise Data Model
Segment of a Project-Level Data Model
8/13/2019 Chapter+1+ +the+Database+Environment
17/30
Chapter 1 2007 by Prentice Hall 17
One customermay place manyorders, but eachorder is placed bya single customer
One-to-manyrelationship
8/13/2019 Chapter+1+ +the+Database+Environment
18/30
Chapter 1 2007 by Prentice Hall 18
One order hasmany order lines;each order line isassociated with asingle order
One-to-manyrelationship
8/13/2019 Chapter+1+ +the+Database+Environment
19/30
Chapter 1 2007 by Prentice Hall 19
One product can be in manyorder lines, eachorder line refersto a single
product
One-to-manyrelationship
8/13/2019 Chapter+1+ +the+Database+Environment
20/30
Chapter 1 2007 by Prentice Hall 20
Therefore, oneorder involvesmany products
and one product isinvolved in manyorders
Many-to-manyrelationship
8/13/2019 Chapter+1+ +the+Database+Environment
21/30
Chapter 1 2007 by Prentice Hall 21
Figure 1-4 Enterprise data model for Figure 1-3 segments
8/13/2019 Chapter+1+ +the+Database+Environment
22/30
Chapter 1 2007 by Prentice Hall 22
Figure 1-5 Components of the Database Environment
8/13/2019 Chapter+1+ +the+Database+Environment
23/30
Chapter 1 2007 by Prentice Hall 23
Components of theDatabase Environment
CASE Tools computer-aided software engineeringRepository centralized storehouse of metadataDatabase Management System (DBMS) softwarefor managing the database
Database storehouse of the data Application Programs software using the dataUser Interface text and graphical displays to usersData/Database Administrators personnel
responsible for maintaining the databaseSystem Developers personnel responsible fordesigning databases and softwareEnd Users people who use the applications anddatabases
8/13/2019 Chapter+1+ +the+Database+Environment
24/30
Chapter 1 2007 by Prentice Hall 24
The Range of Database Applications
Personal databasesWorkgroup databases
Departmental/divisional databasesEnterprise databaseWeb-Enabled database
8/13/2019 Chapter+1+ +the+Database+Environment
25/30
Chapter 1 2007 by Prentice Hall 25
8/13/2019 Chapter+1+ +the+Database+Environment
26/30
Chapter 1 2007 by Prentice Hall 26
Figure 1-6Typical datafrom apersonaldatabase
8/13/2019 Chapter+1+ +the+Database+Environment
27/30
Chapter 1 2007 by Prentice Hall 27
Figure 1-7 Workgroup database with wirelesslocal area network
8/13/2019 Chapter+1+ +the+Database+Environment
28/30
Chapter 1 2007 by Prentice Hall 28
Enterprise Database Applications
Enterprise Resource Planning (ERP)Integrate all enterprise functions
(manufacturing, finance, sales, marketing,inventory, accounting, human resources)
Data WarehouseIntegrated decision support system derivedfrom various operational databases
8/13/2019 Chapter+1+ +the+Database+Environment
29/30
Chapter 1 2007 by Prentice Hall 29
Figure 1-8 An enterprise data warehouse
8/13/2019 Chapter+1+ +the+Database+Environment
30/30
Chapter 1 2007 by Prentice Hall 30
Evolution of DB Systems