Search This Blog

Thursday, September 15, 2016

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



No comments:

Post a Comment