STORING ORGANIZATIONAL INFORMATION

(DATABASES)

CHAPTER 7

               -Information is stored in databases

 Database is maintain information about various type of object, events, people, and places

-Database model

Hierarchical database :

 information is organized into a tree-like structure in such away that it cannot have too many relationships

Network database:

a flexible way of representing object and their relationships

Relational database model:

stores information in the form of logically related two-dimensional tables

-Entity

a person, place, thing, transaction or event about which information is stored

-Attributes

characteristics or properties of any entity class

-Primary key

a field that uniquely identifies a given entity in a table

-Foreign key 

a primary key of one table taht appears an attribute in another table acts to provide a logical relationship among the two table

-Advantages relational database
:increased flexibility
Physical view
logical view

:increased scalability and performance
scalability
performance

:reduced information redundancy
redundancy

:increased information integrity
information integrity
integrity constraint

:increased information security
password
access level
access control

-Database management systems
software through which users and application programs interact with a database

-Data-driven web sites
an interactive web site kept constanly updated and relevant to the needs ot its customers through the use of a database

: development
:content management
:future expandabilit
:minimizing human error
:cutting production and update costs
:more efficient
:improved stability


-Inteligrating information among multiple databases

:integration
forward integration
backward integration