Download Database Development Process

Chapters 1 thru 5
Database Development Processes
Jason C. H. Chen, Ph.D.
Professor of MIS
School of Business Administration
Gonzaga University
Spokane, WA 99258
[email protected]
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
TM 2-1
Figure 1-3: Comparison of enterprise and project
level data models
Segment of an Enterprise Data Model
CUSTOMER
ORDER
M ORDER?
Q1. One CUSTOMER normally places ___
1 CUSTOMER?
Q2. One ORDER normally is placed by __
ORDER
PRODUCT
Q3. One ORDER normally places M
__ PRODUCT?
M ORDER?
Q4. One PRODUCT normally is placed by __
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
TM 2-2
Systems Development Life Cycle
(SDLC)
• Analysis
– Feasibility study (capital, technology, organization, legal etc.)
• Design
– Logical
– Physical
• Implementation
– Coding
– Testing
– Conversion
• Maintenance
– H/S W
– Firm ware
– People ware
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
TM 2-3
Steps in the Database
Development Process
• Enterprise Modeling
• Conceptual Data Modeling
– Cuts across Project Initiation and Planning & Analysis
phases of SDLC
•
•
•
•
•
Logical Database Design (E/R)
Physical Database Design and Creation
Database Implementation
Database Maintenance
Database Growth and Change
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
TM 2-4
The Technology Level of Models
• Conceptual models focus on the underlying
content of an information system with no
assumptions about technology
• Logical models assume a general class of
technology (H/S W independent) – a relational
database and such
• Internal models assume specific technologies –
an Oracle database engine
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
TM 2-5
Three-schema database architecture
External
Schema
Ch. 1,2
Ch.2, 3,4
Meta-data/
Repository/
D.D.
E/R, OO …
Relations
Ch. 5
Database
Internal
Schema
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
N
TM 2-6
Database Schema
• External Schema (during the analysis and logical design phases)
– User Views
– Subsets of Conceptual Schema
– Can be determined from business-function/data entity
matrices
– DBA determines schema for different users
– This is part of people-management in databases
• Conceptual Schema
– ER models (during the analysis phase)
• Physical (Internal) Schema
– Physical structures (during the physical design phase)
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
TM 2-7
EMPLOYEE
composite
multi-valued
e_id
e_name
e_address
dob
date_employed
skill
1234
John smith
502 Boone
Spokane, WA
99258
1-11988
1-1-2005
programming,
painting,
drawing,
5678
Mary Jones
567 SE Main st,
Seattle, WA
98059
2-9-87
3-3-2007
Gardening
EMPLOYEE
e_id
e_name
e_address (street, city, state, zip)
dob
date_employed
{skill}
[years_employed]
[age]
…
derived/
computed
years_employed age
• Should we create “composite”
attributes? (see next slide)?
• Should we create “derived/computed”
attributes and save physically/
permanently in the database and why?
• How to insert values into “multi-valued”
attributes?
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
TM 2-8
Steps of Database Development
…
User view-1
User view-2
User view-3
…
User view-N
…
Conceptual Schema (Model)
Logical Model
(ERD or E/ERD)
Implementation
(w/Physical or Internal Model)
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
TM 2-9
Steps of Database Development (MVC)
(FIVE
figures)
…
User view-1
User view-2
User view-3
…
User view-N
…
Conceptual Schema (Model)
Logical Model
(ERD or E/ERD)
PHASE I
Something
Missed?
Implementation
(w/Physical or InternalModel)
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
PHASE II
TM 2-10
Steps of Database Development
User view-1
User view-2
User view-3
…
…
User view-N
…
Conceptual Schema (Model)
Logical Model
(ERD or E/ERD)
???
Implementation
(w/Physical Model)
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
TM 2-11
Steps of Database Development
User view-1
User view-2
User view-3
…
…
User view-N
…
Conceptual Schema (Model)
Logical Model
(ERD or E/ERD)
(Seven) RelationsTransformation
___________
NORMALIZATION(up to 3NF)
_________________
(more relations
produced)
(more tables
created)
Implementation
__________________ (w/Physical Model)
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
TM 2-12
Figure: 4-22 Steps in Normalization
Table with Multivalued
attributes
First normal
form (1NF)
Second normal
form(2NF)
Third normal
form (3NF)
Boyce-Codd normal
form (BC-NF)
Fourth normal
Form (4NF)
Fifth normal
form (5NF)
Copyright © Addison Wesley Longman, Inc. & Dr. Chen, Business Database Systems
Multivalued
Remove ___________
Attributes
Partial
Remove ___________
Dependencies
Transitive
Remove __________
Dependencies
Remove remaining
anomalies resulting from
multiple candidate keys
Remove Multivalued
Dependencies
Remove Remaining
Anomalies
TM 2-13