CHAPTER 7 : STORING ORGANIZATIONAL INFORMATION ( DATABASE )

Database – Maintains info about various types of objects ,events,people and places.

Database models include :

Hierarchical Database Model 

Network Database Model

Relation Database Model

Entities and Attributes

Entities -  a person , place , thing or event about which info is stored.

Attributes – characteristics or properties of an entity class.

Keys and Relationsips

Primary key -  a field that uniquely identifies a given entity in atable.

Foreign Key – a primary key of one table that appears an attribute in another table and acts.

Relation Database Advantage

-       -   Increase flexibility

-        -  Increased scalability and performance

-       - Reduces info redundancy

  

Database Mangement System

Data Driven Web Sites

-         

        An interactive web site kept constantly updated and relevant to the needs of customer.

Advantage :

1. Development

-    allows the owner to make changes at any time.

2. Content Management

-    Requires a programmer to make updates.

3. Future Expandability

-   Enables the site to grow faster than would be possible with a static site.

4. More Efficient

-   Computers are excellent at keeping volumes of information intact.

Intergrating Information among Multiple Databases

Intergration – allows separate systems to communicate directly with each other.

1. Forward Intergration

-   takes info entered into a given system and sends it auto to all downstream system and processes.

2. Backward Intergration

-   takes info entered into agiven system and sends it auto to all upstream systems and processes.