Summary of Mgt 300

November 06, 2017

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).

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.

Hierarchical Structure

Network Structure

Relational Structure

Entities and Attributes

Entity is a person, place, thing, transaction, or event about which information is stored (The rows in each table contains the entities).

Attributes is characteristics or properties of an entity class (The columns in each table contain the attributes).

Keys and Relationships

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

Primary key – a field (or group of fields) that uniquely identifies 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 relationship among the two tables.

Relational Database Advantages

A) 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

B) 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

C) 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

D) Increased information integrity (quality)

Information integrity – measures the quality of information
Integrity constraint – rules that help ensure the quality of information
Relational integrity constraint-rule that enforces basic and fundamental information-based constraints
Eg. Users cannot create an order for a nonexistent customer ; An order cannot be shipped without an address

E) 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 : Allows the website owner to make changes any time
Content management : A static website requires a programmer to make updates.
Future expandability : Having a data-driven website enables the site to grow faster than would be possible with a static site.
Minimizing human error
Cutting production and update costs
More efficient
Improved stability