PPT Slide
Because data in the data warehouse is accurate as of some moment in time, data found in the warehouse is said to be "time variant".
- Time horizon: five to ten years
- operational: from current values of today up to sixty to ninety days.
- Key structures: Implicity or explicitly contains an element of time, such as day, week, month.
- Cannot be updated: Unlike operational data once correctly recorded, data in the warehouse cannot be updated.