Chapter 7 - Storing Organizational Information - Databas

RELATIONAL DATABASE FUNDAMENTALS

 -    Information is everywhere in an organization-  Information is stored in databasesØ   Database – maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses)

 -     Database models include:

     Ø   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.

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

      

  Ø  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

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
        §  Physical view – deals with the physical storage of information on a                                             storage device
         §  Logical view – focuses on how users logically access information

    Ø  Have multiple logical views

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

REDUCED INFORMATION REDUNDANCY

-      Databases reduce information redundancyØ  Redundancy – the duplication of information or storing the same information in multiple placesØ  Inconsistency is one of the primary problems with redundant information

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