CHAPTER SEVEN : STORING ORGANIZATIONAL INFORMATION

RELATIONAL DATABASE FUNDAMENTALS

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

Ø  The rows in each table contains the entities

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

Ø  The columns in each table contain the attributes

KEYS AND RELATIONSHIPS

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

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

Ø  Foreign key – a primary key of one table that appears an attribute in another table and acts to provide a logical relationships among the two tables 

RELATIONAL DATABASE ADVANTAGES

-    Database advantages from a business perspective include;

Ø  Increased flexibility

Ø  Increased scalability and performance

Ø  Reduced information redundancy

Ø  Increased information integrity (quality)

Ø  Increased information security

I)INCREASED FLEXIBILITY

-     A well-designed database should;

Ø  Handle changes quickly and easily

Ø  Provide users with different views

Ø  Have only one physical views

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

Ø  Have multiple logical views

o   Logical view – focuses on how users logically access information

II) INCREASED SCALABILITY AND PERFORMANCE

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

Ø  Scalability – refers to how well a system can adapt to increased demands

Ø  Performance – measures how quickly a system performs a certain process or transaction

III) REDUCED INFORMATION REDUNDANCY

-      Databases reduce information redundancy

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

-     Inconsistency is one of the primary problems with redundant information

IV) INCREASED INFORMATION INTEGRITY

-      Information Integrity – measure the quantity of information

-      Integrity Constraint – rules that help ensure the quality of information

I) Relational integrity constraint – rule that enforce basic and fundamental information-based constraints

ii) Business-critical integrity constraint – rule that enforces business rules vital to an organization’s success and often required more insight and knowledge than relational integrity constraints.

V) INCREASED INFORMATION SECURITY

-      Information is an organization asset and must be protected

-      Databases offer several security features including;

Ø  Password – provides authentication of the user

Ø  Access level – determines who has access to the different types of information

Ø  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 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 INTELLIGENT

-         BI in a data-driven Web site

INTEGRATING INFORMATION AMONG MULTIPLE DATABASES

Integration – allows separate systems to communicate directly with each other

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

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

Building a central repository specifically for integrated information