chapter 7

CHAPTER 7

Chapter 7 - Storing Organizational Information - Database

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 contains the entities

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

:) 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

:)  Primary key – a fields (or group of fields) that uniquely identities 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 relationships among the two tables 

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 views

:)  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

INCREASED INFORMATION SECURITY

-      Information is an organization 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 database

DATA-DRIVEN WEB SITE BUSINESS ADVANTAGES

-         Development

-         Content Management

-         Future Expandability

-         Minimizing Human Error

-         Cutting Production and Update Costs

-         More Efficient

-         Improved Stability