Primary database model employed
Relational
Relational
Level of detail
Detailed transactions
Often summarized data
Availability of historical data
Very limited—typically a few weeks or months
Multiple years
Update process
On-line, ongoing process as transactions are captured
Periodic process, once per week or once per month
Ease of update
Routine and easy
Complex, must combine data from many sources; data must go through a data cleanup process
Data Integrity issues
Each individual transaction must be closely edited
Major effort to clean and integrate data from multiple sources