CHAPTER 7 : STORING ORGANIZATIONAL INFORMATION

Learning Outcomes

1.  Define the fundamental concepts of the relational database model
2. Evaluate the advantages of the relational database model
3. Compare relational integrity constraints and business-critical integrity constraints
4. Describe the benefits of a data driven Web site
5. Describe the two primary methods for integrating information across multiple databases

Relational Database Fundamentals

-Information is everywhere in an organization

-Information is stored in databases

Database – maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses)

- Database models include:

1. Hierarchical database model – information is organized into a tree-like structure (using parent/child relationships) in such a way that it cannot have too many relationships
2. Network database model – a flexible way of representing objects and their relationships
3. Relational database model – stores information in the form of logically related two-dimensional tables

Entities and Attributes

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

• The rows in each table contain the entities
• In Figure 7.1 CUSTOMER includes Dave’s Sub Shop and Pizza Palace entities

Attributes (fields, columns) – characteristics or properties of an entity class

•        The columns in each table contain the attributes
•        In Figure 7.1 attributes for CUSTOMER include Customer ID, Customer Name, Contact Name

Keys and Relationships

- Primary keys and foreign keys identify the various entity classes (tables) in the database

Primary key – a field (or group of fields) that uniquely identifies a given entity in a table

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

to provide a logical relationship among the two tables

- Potential relational database for Coca-Cola

Relational Database Advantages

- Database advantages from a business perspective include

•        Increased flexibility
•        Increased scalability and performance
•        Reduced information redundancy
•        Increased information integrity (quality)
•        Increased information security

Increased Flexibility

-A well-designed database should:

1.        Handle changes quickly and easily
2.        Provide users with different views
3.        Have only one physical view

•      Physical view – deals with the physical storage of information on a storage device

       4. Have multiple logical views

•      Logical view – focuses on how users logically access information 

Increased Scalability and Performance

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

•     Scalability – refers to how well a system can adapt to increased demands
•     Performance – measures how quickly a system performs a certain process or transaction

Reduced Information Redundancy

- Databases reduce information redundancy

       Redundancy – the duplication of information or storing the same information in multiple places

- Inconsistency is one of the primary problems with redundant information

Increase Information Integrity (Quality)

Information integrity – measures the quality of information

Integrity constraint – rules that help ensure the quality of information

1.        Relational integrity constraint
2.        Business-critical integrity constraint

Increased Information Security

- Information is an organizational asset and must be protected

- Databases offer several security features including:

•      Password – provides authentication of the user
•      Access level – determines who has access to the different types of information
•      Access control – determines types of user access, such as read-only access

Database Management Systems

Database management systems (DBMS) – software through which users and application

programs interact with a database

DATA-DRIVEN WEB SITES

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

Data-Driven Web Site Business Advantages

- Development

- Content Management

- Future Expandability

- Minimizing Human Error

- Cutting Production and Update Costs

- More Efficient

- Improved Stability

Data-Driven Business Intelligence

- BI in a data-driven Web site

Integrating Information among Multiple Databases

- Integration – allows separate systems to communicate directly with each other

•       Forward integration – takes information entered into a given system and sends it automatically to all downstream systems and processes
•      Backward integration – takes information entered into a given system and sends it automatically to all upstream systems and processes

Forward integration & Backward integration

- Building a central repository specifically for integrated information