Data Warehousing
- Purpose: to support on-line analytical processing
- OLTP
- used for operational transactions
- large number of transactions must be processed efficiently
- small changes in database
- Example: adding a reservation, depositing a check
- OLAP
- used for decision support
- analyze current and historical data
- identify trends
- create useful summaries
- Examples
- credit card usage for unusual activities indicating misuse of a
lost or stolen card
- customer records to identify promising customers for new promotion
- What is a data warehouse?
- a highly structured, very large database containing subject oriented
data used to aid decision making
- size: 50 GB to terrabytes
- historical information
- read-only information
- ease of use: business-oriented query tools: GUI, bar charts, histograms