Agile Software Development
individuals and interactions over processes and tools, working software over comprehensive documentation, customer collaboration over contract negotiation, and response to change over following a plan
Applications Programs
software using the data
CASE Tools
computer-aided software engineering
Conceptual Schema
a detailed, technology-independent specification of the overall structure of organizational data
Constraint
a rule that cannot be violated by database users
Data
stored representations of objects and events that have meaning and importance in the user's environment
Data Administrators
personnel responsible for maintaining the database
Data Independence
the separation of data descriptions from the application programs that use the data
Data Model
graphical systems used to capture the nature and relationships among data
Data Modeling and Design Tools
software tools that provide automated support for creating data models
Data Warehouse
an integrated decision support database whose content is derived from the various operational databases
-detached from operational data; operation DBs data dump
-stores historical data
-only used for data analysis, not for operation
Database
an organized collection of logically related data
Database Application
an application program (or set of related programs) that is used to perform a series of database activities (create, read, update, and delete) on behalf of database users
Database Management System (DBMS)
a software system that is used to create, maintain, and provide controlled access to user databases
Duplication of Data
different systems/programs have separate copies of the same data
End Users
people who use the applications and databases
Enterprise Data Modeling
the first step in database development, in which the scope and general contents of organizational databases are specified
Enterprise Resource Planning (ERP)
a business management system that integrates all functions of the enterprise, such as manufacturing, sales, finance, marketing, inventory, accounting, and human resources. ERP systems are software applications that provide the data necessary for the enterprise to examine and manage its activities.
-Support organization-wide operation
-Focus on integration of all enterprise functions (manufacturing, finance, sales, marketing, inventory, accounting, human resources)
-Work with the operational data of the enterprise
Excessive Program Maintenance
-80% of information systems budget
-personnel cost (it takes a long time to understand a system)
Entity
a person, a place, an object, an event, or a concept in the user environment about which the organization wishes to maintain data
Information
data that have been processed to increase the knowledge of the person who uses the data
Lengthy Development Times
programmers must design their own file formats
Limited Data Sharing
no centralized control of data
Logical Schema
the representation of a database for a particular data management technology
Metadata
data that describe the properties or characteristics of end-user data and the context of those data
Program-Data Dependence
all programs maintain metadata for each file they use
Physical Schema
specifications for how data from a logical schema are stored in a computer's secondary memory by a database management system
Project
A planned undertaking of related activities to reach an objective that has a beginning and an end
Prototyping
an iterative process of systems development in which requirements are converted to a working system that is continually revised through close work between analysts and users
Relational Database
a database that represents data as a collection of tables in which all data relationships are represented by common values in related tables
(Ex. Oracle, DB2, SQL Server)
-Easy to understand and use
-Good for most general purpose business uses
System Developers
personnel responsible for designing databases and software
Repository
a centralized knowledge base of all data definitions, data relationships, screen and report formats, and other system components
User Interface
text and graphical displays to users
Systems Development Life Cycle (SDLC)
the traditional methodology used to develop, maintain, and replace information systems
Why NOT file systems?
#NAME?
User View
a logical description of some portion of the database that is required by a user to perform some task
History of Database Systems
Flat Files: '60s - '80s
Hierarchical: '70s - '90s
Network: '70s - '90s
Relational: '80s - present
Object-Oriented: '90s - present
Object-Relational: '90s - present
Data Warehousing: '80s - present
Web-Enabled: '90s - present