MGT 300 CHAPTER7 : Storing Organizational Information

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

Entities and Attributes

v  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

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

A well-designed database should:

Handle changes quickly and easily

Provide users with different views

Have only one physical view

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

Have multiple logical views

v  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

§  Increased 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

Database Management Systems

v  Database management systems (DBMS) – software through which users and application programs interact with a database

DATA-DRIVEN WEB SITES

v  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

v  Development

v  Content Management

v  Future Expandability

v  Minimizing Human Error

v  Cutting Production and Update Costs

v  More Efficient

v  Improved Stability

Data-Driven Business Intelligence

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

v  Forward integration

v  Backward integration

v  Building a central repository specifically for integrated information