All about Me, Myself and I ^_^: MGT300 Chapter 7 - Storing Organizational Information

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

2. 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

3. 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

4. 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