storing organizational information - database

assalamualikum everyone...

for this chapter i would like to share with u all about database... =)
everyone know that information is everywhere in an organization..

DATABASE : maintains information about various types of objects (inventory), events   (transactions), people (employees) and places (warehouse)




DATABASE models include :

1. Hierachical database model :


                  

2. Network database model :


                            

3. Relational database model :


                     


Entity        : a person, place, things, transaction about which information is stored.

Attributes  : characteristics or properties of an entity class.

Primary key and foreign keys identify the various entity classes in the database.

A database must scale to meet increased demand, while maintaining acceptable performance levels.

Database reduces information REDUNDANCY. Redundancy means the duplication of information or storing the same information in multiple places.