CHAPTER 7 :STORING ORGANIZATIONAL INFORMATION -DATABASES

LEARNING OUTCOMES 

7.1 Define the fundamental concepts of the relational database model.

7.2 Evaluate the advantages of the relational database model.

7.3 Compare relational integrity constraints & business-critical integrity constraints .

7.4 Describe the benefits of a data driven Website .

7.5 Describe the two primary methods for integrating information across multiple databases.

1.Relational Database Fundamentals

a)Information is everywhere in an organization.

b)Information is stored in databases.
   -Database: maintains information about various types of objects,events,people and places.

c)Database models include:
  🔺 i)Hierarchical database model- information is organized into a tree-like structure it cannot       have too many relationships.
  🔺 ii)Network database model -a flexible way of representing objects & their relationships.
  🔺 iii)Relational database model-stores information in the form of logically related 2-dimensional tables.

c.i)Hierarchical Structure

                                          ⤷cannot too many relationship 


c.ii)Network Database Model

                      ⤍can be too many relationship because its flexible


c.iii)Relational Database Model

⤕can be related with different tables

2.ENTITIES AND ATTRIBUTES 

➤ Entity- a person,thing, place ,transaction or event with information is stored.

↝ Entity is the rows in each table contain the entities.

➤ Attribute -characteristics or properties of an entity class.

⇾Attributes is the column in each table contain the attributes.

3.Keys & Relationship

➦Primary key- unique identifies a given entity in a table (ID number,matrix number).

➦Foreign key- a primary key that appears an attribute in another table and to provide a logical relationship among the two tables.

4.Relational Database Advantages

➯a)Increased flexibility -different users have different needs.

                           -one physical view multiple logical view and flexible to users.

                                       -eg:UiTM lecturers view on iLearn different,student view on iLearn different but in physical view.

➯b)Increased scalability & performance 

         -Scalability : system can adapt to increased demands.

         -Performance :measures how quickly a system performs a certain process/transaction.

➯c)Reduced Information Redundancy 

   - Get same information ,eg:Customers name will duplicate can avoid by primary key.

   -Goal: eliminate information redundancy by recording each piece of information in one place.

➯d)Increase information integrity (quality)
     - Information integrity: measures the quality of information.
     - Integrity constraint : rules that help ensure the quality of information.
       i)Relational integrity constraint -rule that enforces basic & fundamental information -               based constraints.
      ii)Business-critical integrity constraint -rule that enforce business rules vital to an                         organization's knowledge than relational integrity constraints.

➱e)Increased information security- asset from authorized users not all can access because password ,access level and access control .Eg : Lower level only can read but upper level can update or delete.

5.Database management systems (DBMS)

➜Use DBMS to get information it can update ,delete ,print but still have to access level.

➜Users send request to DBMS then DBMS resend the information that users wants.

*Indirect interaction users NOT directly database but application directly to database.

*Direct interaction users directly to database.

6.Data-driven web sites: an interactive web site kept constantly updated and relevant to the needs of its customers through the use of a database .

i)Dynamic information- data always changes.
ii)Static information- data fixed cannot changes such as Wikipedia.

7.Data-Driven Web Site Business Advantages

➔Development :
➔Content management 
➔Future expandability 
➔Minimizing human error 
➔Cutting production & update costs
➔More efficient 
➔Improve stability 

8.Data-Driven Business Intelligence 

*Application that helps to make decisions.


9.Integrating information among multiple databases

*Integration-allows separate systems to communicate directly with each other.
a)Forward integration -
b)Backward integration - 

9.a)Forward integration 

*Follow the sequence where as start from sales and ending by billing system.
*It also relate each other.

9.b)Backward integration 

*Backward integration recheck everything where as start from billing system and ending by sales system.

c)Building a central repository specifically for integrated information.

*Once update to central repository (customer information system) automatically update to salwes system,order entry system,order fulfillment system and billing system.

d)Advantages :

 -Can save time
 -Reduce redundancy 
 -To get high quality