chapter 2 database development process
TRANSCRIPT
-
7/28/2019 Chapter 2 Database Development Process
1/26
2009 Pearson Education, Inc. Publishing as Prentice Hall1
Chapter 2:The Database Development Process
Modern Database Management
9th Edition
Jeffrey A. Hoffer, Mary B. Prescott,Heikki Topi
-
7/28/2019 Chapter 2 Database Development Process
2/26
2
Enterprise Data Model
First step in database development
Specifies scope and general content
Overall picture of organizational data at high level of
abstraction
Entity-relationship diagram
Descriptions of entity types
Relationships between entities
Business rules
-
7/28/2019 Chapter 2 Database Development Process
3/26
3
Figure 2-1 Segment from enterprise data model
Enterprise data model
describes the high-
level entities in an
organization and therelationship between
these entities
-
7/28/2019 Chapter 2 Database Development Process
4/26
4
Information Systems Architecture
(ISA)
Conceptual blueprint for organizations desiredinformation systems structure
Consists of: Data (e.g. Enterprise Data Modelsimplified ER Diagram)
Processesdata flow diagrams, process decomposition, etc.
Data Networktopology diagram (like Fig 1-7)
Peoplepeople management using project managementtools (Gantt charts, etc.)
Events and points in time (when processes are performed)
Reasons for events and rules (e.g., decision tables)
-
7/28/2019 Chapter 2 Database Development Process
5/26
5
Information Engineering
A data-oriented methodology to create andmaintain information systems
Top-down planninga generic IS planningmethodology for obtaining a broad understandingof the IS needed by the entire organization
Four steps to Top-Down planning: Planning
Analysis
Design
Implementation
-
7/28/2019 Chapter 2 Database Development Process
6/26
6
-
7/28/2019 Chapter 2 Database Development Process
7/26
7
Identify Strategic Planning Factors
(Table 2-2)
Organization goalswhat we hope to
accomplish
Critical success factorswhat MUST work in
order for us to survive
Problem areasweaknesses we now have
-
7/28/2019 Chapter 2 Database Development Process
8/26
8
Identify Corporate Planning Objects
(Table 2-3)
Organizational unitsdepartments
Organizational locations
Business functionsgroups of business
processes
Entity typesthe things we are trying to modelfor the database
Information systemsapplication programs
-
7/28/2019 Chapter 2 Database Development Process
9/26
9
Develop Enterprise Model
Functional decomposition
Iterative process breaking system description intofiner and finer detail
Enterprise data model
Planning matrixes
Describe interrelationshipsbetween planning objects
-
7/28/2019 Chapter 2 Database Development Process
10/26
10
Planning Matrixes
Describe relationships between planningobjects in the organization
Types of matrixes:
Location-to-function
Unit-to-function
IS-to-data entity
Supporting function-to-data entity IS-to-business objective
-
7/28/2019 Chapter 2 Database Development Process
11/26
11
Example Business Function-to-Data
Entity Matrix (Fig. 2-3)
-
7/28/2019 Chapter 2 Database Development Process
12/26
12
Two Approaches to Database and IS
Development SDLC
System Development Life Cycle Detailed, well-planned development process Time-consuming, but comprehensive Long development cycle
Prototyping Rapid application development (RAD) Cursory attempt at conceptual data modeling Define database during development of initial prototype Repeat implementation and maintenance activities with new
prototype versions
-
7/28/2019 Chapter 2 Database Development Process
13/26
13
Systems Development Life Cycle
(see also Figures 2.4, 2.5)
Planning
Analysis
Physical Design
Implementation
Maintenance
Logical Design
-
7/28/2019 Chapter 2 Database Development Process
14/26
14
Systems Development Life Cycle
(see also Figures 2.4, 2.5) (cont.)
Planning
Analysis
Physical Design
Implementation
Maintenance
Logical Design
Planning Purposepreliminary understanding
Deliverablerequest for study
Database activityenterprise modeling and
early conceptual data
modeling
-
7/28/2019 Chapter 2 Database Development Process
15/26
15
Systems Development Life Cycle
(see also Figures 2.4, 2.5) (cont.)
Planning
Analysis
Physical Design
Implementation
Maintenance
Logical Design
Analysis
Purpose
thorough requirements analysis and
structuring
Deliverablefunctional system specifications
Database activity
thoroughand integrated conceptual
data modeling
-
7/28/2019 Chapter 2 Database Development Process
16/26
16
Systems Development Life Cycle
(see also Figures 2.4, 2.5) (cont.)
Planning
Analysis
Physical Design
Implementation
Maintenance
Logical DesignLogical Design
Purpose
information requirements elicitationand structure
Deliverabledetailed design specifications
Database activity
logical database design
(transactions, forms,
displays, views, data
integrity and security)
-
7/28/2019 Chapter 2 Database Development Process
17/26
17
Systems Development Life Cycle
(see also Figures 2.4, 2.5) (cont.)
Planning
Analysis
Physical Design
Implementation
Maintenance
Logical Design
Physical Design
Purpose
develop technology and
organizational specifications
Deliverableprogram/data
structures, technology purchases,
organization redesigns
Database activity
physical database design (define
database to DBMS, physical
data organization, database
processing programs)
-
7/28/2019 Chapter 2 Database Development Process
18/26
18
Systems Development Life Cycle
(see also Figures 2.4, 2.5) (cont.)
Planning
Analysis
Physical Design
Implementation
Maintenance
Logical Design
Implementation
Purpose
programming, testing, training,installation, documenting
Deliverableoperational programs,
documentation, training materials
Database activity
database implementation,
including coded programs,
documentation,
installation and conversion
-
7/28/2019 Chapter 2 Database Development Process
19/26
19
Systems Development Life Cycle
(see also Figures 2.4, 2.5) (cont.)
Planning
Analysis
Physical Design
Implementation
Maintenance
Logical Design
Maintenance
Purposemonitor, repair, enhance
Deliverableperiodic audits
Database activity
database maintenance,
performance analysis
and tuning, error
corrections
-
7/28/2019 Chapter 2 Database Development Process
20/26
20
CASE
Computer-Aided Software Engineering (CASE)software tools providing automated support for
systems development
Three database features: Data modelingdrawing entity-relationship diagrams
Code generationSQL code for table creation
Repositoriesknowledge base of enterpriseinformation
-
7/28/2019 Chapter 2 Database Development Process
21/26
21
Packaged Data Models
Model components that can be purchased,customized, and assembled into full-scale datamodels
Advantages
Reduced development time
Higher model quality and reliability
Two types:
Universal data models Industry-specific data models
-
7/28/2019 Chapter 2 Database Development Process
22/26
22
Managing Projects
Projecta planned undertaking of relatedactivities to reach an objective that has abeginning and an end
Involves use of review points for:
Validation of satisfactory progress Step back from detail to overall view Renew commitment of stakeholders
Incremental commitmentreview of systemsdevelopment project after each developmentphase with rejustification after each phase
-
7/28/2019 Chapter 2 Database Development Process
23/26
-
7/28/2019 Chapter 2 Database Development Process
24/26
24
Database Schema
External Schema User Views
Subsets of Conceptual Schema
Can be determined from business-function/data entitymatrices
DBA determines schema for different users
Conceptual Schema E-R modelscovered in Chapters 3 and 4
Internal Schema
Logical structurescovered in Chapter 5 Physical structurescovered in Chapter 6
-
7/28/2019 Chapter 2 Database Development Process
25/26
25
Different people
have differentviews of the
databasethese
are the external
schema
The internal
schema is the
underlying
design andimplementation
Figure 2-7 Three-schema architecture
-
7/28/2019 Chapter 2 Database Development Process
26/26