CHAPTER 7 ( Storing Organizational Information )

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 and business-critical integrity constraints

7.4  Describe the benefits of a data driven Web site

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

Relational Database Fundamentals

v Information is everywhere in an organization

v Information is stored in databases

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

v Database models include:

§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

§Network database model – a flexible way of representing objects and their relationships

§Relational database model – stores information in the form of logically related two-dimensional tables

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

v 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

Relational Database Advantages

v 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

v A well-designed database should:\§Handle changes quickly and easily

§Provide users with different views

§Have only one physical view

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

§Have multiple logical views

•Logical view – focuses on how users logically access information

Increased Scalability and Performance

v 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

v Databases reduce information redundancy

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

v Inconsistency is one of the primary problems with redundant information

Increase Information Integrity (Quality)

v Information integrity – measures the quality of information

v Integrity constraint – rules that help ensure the quality of information

§Relational integrity constraint

§Business-critical integrity constraint

Increased Information Security

v Information is an organizational asset and must be protected

v 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

Data-Driven Web Site Business Advantages

v Development

v Content Management

v Future Expandability

v Minimizing Human Error

v Cutting Production and Update Costs

v More Efficient

v Improved Stability

Integrating Information
among Multiple Databases

v 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