Module #1 Flashcards
organized collection of logically related data
Database
stored representations of meaningful objects and events
Data
data processed to increase knowledge in the person using the data
Information
data that describes the properties and context of user data
Metadata
All programs maintain metadata for each file they use
Program Data Dependence
Different systems/programs have separate copies of the same data
Duplication of Data
No centralized control of data
Limited Data Sharing
Programmers must design their own file formats
Lengthy Development Times
80% of information systems budget
Excessive Program Maintenance
Disadvantages of File Processing
- Program Data Dependence
- Limited Data Sharing
- Lengthy Development Times
- Excessive Program Maintenance
Central Repository of shared data
The Database Approach
Data is managed by a controlling agent
The Database Approach
Stored in a standardized convenient form
The Database Approach
A software system that is used to create, maintain, and provide controlled access to user databases
Database Management System
Graphical System capturing nature and relationship of data
Data models
high-level entities and relationships for the organization
Enterprise Data Model
more detailed view, matching data structure in database or data warehouse
Project Data Model
Composed of attributes
Entities
Noun form describing a person, place, object, event, or concept
Entities
Database technology involving tables (relations) representing entities and primary/foreign keys representing relationships
Relational Databases
computer aided software engineering
CASE Tools
centralized storehouse of metadata
Repository
software using the data
Application Programs
text and graphical displays to users
User Interface
personnel responsible for maintaining the
database
Data/Database Administrators
people who use the applications and databases
End Users
personnel responsible for designing databases and software
System Developers
SDLC
System Development Life Cycle
Detailed, well planned development process
Time consuming, but comprehensive
Long development cycle
SDLC
Rapid application development
RAD
Cursory attempt at conceptual data modeling
Prototyping
Define database during development of initial prototype
Prototyping
Repeat implementation and maintenance activities with new prototype versions
Prototyping
System Development Life Cycle
- Planning
- Analysis
- Logical Design
- Physical Design
- Implementation
- Maintenance
User Views
External Schema
Subsets of Conceptual Schema
External Schema
Can be determined from business function/data entity matrices
External Schema
E R models
Conceptual Schema
Logical structures
Internal Schema
Physical structures
Internal Schema
is the underlying design and implementation
Internal Schema
Different people have different views of the database
External Schema
a planned undertaking of related activities to reach an objective that has a beginning and an end
Project
Enterprise resource planning (ERP) systems
Enterprise applications
Range of Database Applications
- Personal databases
- Multitier client/server databases
- Enterprise applications
Data warehousing implementations
Enterprise applications
Executed during analysis, design, and implementation
Managing Projects
Initiated and planned in planning stage of SDLC
Managing Projects
Closed at the end of implementation
Managing Projects
