Concept
Dimensions in data management and data warehousing contain relatively static data about such entities as geographical locations, customers, or products. Data captured by Slowly Changing Dimensions (SCDs) change slowly but unpredictably, rather than according to a regular schedule.
Type
Type 0: Retain Original
As Date/Area Dimension Attributes
Type 1: Overwritten
Type 2: Add New Row
Type 3: Add New Attribute
Type 4: Add Mini-Dimension
Type 5: Add Mini-Dimension and Type 1 Outrigger
Type 6: Add Type 1 Attributes to Type 2 Dimension
Type 7: Dual Type 1 and Type 2 Dimensions
Other
- History / Snapshot / Zipper Table
Links
- Slowly changing dimension
- Slowly Changing Dimensions Are Not Always as Easy as 1, 2, 3
- Design Tip #152 Slowly Changing Dimension Types 0, 4, 5, 6 and 7
- Author：HyperJ
- Source：HyperJ’s Blog
- Link：Slowly Changing Dimensions (SCDs)