Notes
Outline
Databases
Uses, structures, and terminology
Databases
What kinds of information are collected by typical businesses?
How could that information be used to identify your best customers?
The Problem
Data is collected in numerous systems
Each system has its own purpose
Each system has its own needs (usually speed)
Consequences are data redundancy, data integrity, and data isolation
The ultimate consequence is bad decisions – poor service and weak profits.
Database structures
Data elements need to be grouped logically
Entity- relationship models show groups
Normalization rules help define groups
Example:  Fred Smith buys Prod#349 from Nabisco, Prod#1128 from Pepsi and Prod#19 from Heinz.  What data structures would be necessary to total his purchase, update our inventory, and update information about his buying habits?
Database Management Systems
4 parts:
Data Model – (selected structures)
Data Definition Language
Data Manipulation Language
Data Dictionary
Data Models
Hierarchical – (Tree)
Network
Relational
Data Warehouses
Usually longitudinal views of selected data elements.
Searched for trends and relationships
Selection of data elements frames most likely questions
Advanced statistical functions used to tease out relationships
Data Mining
Search for
Classification
Clusters
Associations
Sequences
Forecasts
Example – processes of Amazon.com