CHAPTER 7 : STORING ORGANIZATIONAL INFORMATION - DATABASES

What is 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)

RELATIONAL DATABASE FUNDAMENTALS

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 contain 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 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

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 view – deals with the physical storage of
  information on a storage device

· Have multiple logical views - 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

Increase Information Integrity (Quality)

Information integrity – measures the quality of information

Integrity constraint – rules that help ensure the quality of information

· Relational integrity constraint

· Business-critical integrity constraint

Increased Information Security

Information is an organizational 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 (DBMS) – software through which users and application programs interact with a database

DATA-DRIVEN WEBSITES

Data-driven websites – an interactive website kept constantly updated and relevant to the needs of its customers through the use of a database.

DATA-DRIVEN BUSINESS INTELLIGENCE