Chapter 7 Storing Organizational Information - Databases

Chapter 7 

Storing Organizational Information - Databases 

Relational Database Fundamentals 

q Information is everywhere in an organization

q Information is stored in databases

vDatabase – maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses)HG

Database models

§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

qEntity – a person, place, thing, transaction, or event about which information is stored

♠The rows in each table contain the entities

♠Customer includes Dave’s Sub Shop and Pizza Palace entities

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

♠The columns in each table contain the attributes

♠Attributes for customer include Customer ID, Customer Name, Contact Name

Relational Database Advantages

ÁDatabase advantages from a business perspective

q Increased flexibility

q Increased scalability and performance

q Reduced information redundancy

q Increased information integrity (quality)

q Increased information security

Increased Flexibility
©A well-designed database should:
vHandle changes quickly and easily
vProvide users with different views
vHave only one physical view

   ¨Physical view – deals with the physical storage of information on a storage device eg hard disk

vHave multiple logical views

   ¨Logical view – focuses on how users logically access information

vEg: a mail-order buss- 2 people view diff format (logical views) but same physical view

Increased Scalability and Performance

   ©A database must scale to meet increased demand,  while maintaining acceptable performance levels

ØScalability – refers to how well a system can adapt to increased demand

ØPerformance – measures how quickly a system performs a certain process or transaction

 Reduced Information Redundancy

qDatabases reduce information redundancy

Redundancy – the duplication of information or storing the same information in multiple places

qInconsistency is one of the primary problems with redundant information-difficult to decide which is most current and most accurate

Increase 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

Business-critical integrity constraint -rule that enforce business rules vital to an organization’s success and often require more insight and knowledge than relational integrity constraints

Eg. Product returns are not accepted for fresh product 15 days after purchase; A discount maximum of 20 percent.

Database Management Systems

Database management systems (DBMS) – software through which users and application programs interact with a database

DATA-DRIVEN WEB SITES

qData-driven Web sites – an interactive Web site kept constantly updated and relevant to the needs of its customers through the use of a database

Data-Driven Web Site Business Advantages

 vDevelopment: Allows the Web site owner to make changes any time—all without having to rely on a developer or knowing HTML programming.

vContent management: A static Web site requires a programmer to make updates. This adds an unnecessary layer between the business and its Web content, which can lead to misunderstandings and slow turnarounds for desired changes.

vFuture expandability: Having a data-driven Web site enables the site to grow faster than would be possible with a static site.  Changing the layout, displays, and functionality of the site (adding more features and sections) is easier with a data-driven solution.

vMinimizing human error: A well-designed, data-driven Web site will have ”error trapping” mechanisms to ensure that required information is filled out correctly and that content is entered and displayed in its correct format.

vCutting production and update costs: A data-driven Web site can be updated and ”published” by any competent data entry or administrative person. In addition to being convenient and more affordable, changes and updates will take a fraction of the time that they would with a static site.

vMore efficient: With a data-driven solution, the system keeps track of the templates, so users do not have to.

vImproved Stability: With a data-driven Web site, there is peace of mind, knowing the content is never lost—even if your programmer is.

Data-Driven Business Intelligence

BI in a data-driven Web site

Integrating Information among Multiple Databases

vIntegration – allows separate systems to communicate directly with each other

üForward integration – takes information entered into a given system and sends it automatically to all downstream systems and processes

üBackward integration – takes information entered into a given system and sends it automatically to all upstream systems and processes

vWithout integration, an organization will:

üSpend considerable time entering the same info in multiple system

üSuffer from the low quality and inconsistency typically embedded in redundant info.

Forward and Backward integration

Building a central repository specifically for integrated information