2. 2
Where we are now
ā¢ Database environment
ā introduction to database
ā¢ Database development process
ā steps to develop a database
ā¢ Conceptual data modeling
ā entity-relationship (ER) diagram; enhanced ER
ā¢ Logical database design
ā transforming ER diagram into relations; normalization
ā¢ Physical database design
ā technical specifications of the database
ā¢ Database implementation
ā Structured Query Language (SQL), Advanced SQL
ā¢ Advanced topics
ā data and database administration
3. 3
Database Development Process
ā¢ Information Systems Architecture
ā¢ Information Systems Planning
ā¢ Systems Development Life Cycle
ā¢ Prototyping
ā¢ People involved in database development
ā¢ Three-schema database architecture
ā¢ Three-tiered database location architecture
5. 5
Information Systems Architecture
ā¢ overall blueprint or plan for an organizationās
information systems
ā¢ developed during IS planning
ā¢ consists of
ā Data (Enterprise Data Model)
ā Processes (that manipulate data, e.g. data flow diagrams)
ā Network (data communication topology diagram)
ā People (perform processes or are source or receiver of data)
ā Events and points in time (when processes are performed)
ā Reasons for events and rules (e.g. decision tables)
6. 6
Fig. 1-3: Segment from Enterprise Data Model
(shows the high-level entities and their relationships)
11. 11
Information Systems Planning
ā¢ Align IT with the business strategies of the organization
ā¢ Three steps:
1. Identify strategic planning factors
ļ¬ Organization goals (what we hope to achieve)
ļ¬ Critical success factors (what must work in order to meet the goals)
ļ¬ Problem areas (what are the current weaknesses)
2. Identify corporate planning objects
ļ¬ Organizational units (departments of the organization)
ļ¬ Organizational locations (places of operation)
ļ¬ Business functions (processes that support the organizationās mission)
ļ¬ Entity types (data on people, places, and things managed by the
organization
ļ¬ Information systems
15. 15
Information Systems Planning (cont.)
3. Develop an enterprise model
ļ¬ Functional decomposition of business functions
ļ¬ Enterprise data model
ā Entity-relationship diagram
ā Descriptions of entity types
ā Relationships between entities
ā Business rules
16. 16
Process decomposition of an order fulfillment
function (Pine Valley Furniture)
Decomposition -- breaking
business functions into
smaller tasks in a
hierarchical structure chart
17. 17
Figure 1-3: Segment from enterprise data model
Enterprise data model describes
the entities in an organization
and the relationship between
these entities
18. 18
Approaches to Database
Development
ā¢ System Development Life Cycle (SDLC)
ā Detailed, well-planned development process
ā Time-consuming, but comprehensive
ā Long development cycle
ā¢ Prototyping
ā Rapid application development (RAD) method
ā Cursory attempt at conceptual data modeling
ā Define database during development of initial prototype.
ā Repeat implementation and maintenance activities with new
prototype versions
21. 21
People Involved in
Database Development
ā¢ Business analysts/Systems analysts
ā work with management and users to analyze information
requirements
ā¢ Database analysts
ā concentrate on requirements and design for database
ā¢ Users
ā provide assessment of their information needs
ā¢ Programmers
ā¢ Database/Data administrators
ā¢ Other technical experts
ā systems programmers, network administrators, testers, technical
writers
22. 22
Three Schema Architecture for
Database Development
ā¢ All views of the same database
ā¢ Conceptual schema
ā technology independent
ā analysis phase
ā¢ External schema
ā one or more user views
ā each user view is a subset of conceptual schema
ā logical design phase
ā¢ Internal schema
ā physical design phase
ā how data are stored in a computerās secondary memory
25. 25
Three-Tiered Database
Location Architecture
ā¢ Where to store the data during physical database design
ā¢ Client tier
ā presentation tier
ā desktop or notebook computer manages user interface and
localized data
ā¢ Application/Web tier
ā process services tier
ā provides access from client tier to data in enterprise tier
ā¢ Enterprise tier
ā data services tier
ā minicomputer or mainframe manages organization data
27. 27
Review Questions
ā¢ What is an information systems architecture?
ā¢ What are the 3 steps in information systems planning?
ā¢ What are the 3 planning factors?
ā¢ What are the 5 planning objects?
ā¢ What are the two approaches to database development?
ā¢ Who are the people involved in database development?
ā¢ What is the 3-schema database architecture?
ā¢ What is the 3-tiered database location architecture?