Chapter 7 Storing Organizational Information

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:

• 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

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:

• 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

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

• Relational integrity constraint
• 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

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