Dw design 3_surro_keys
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Surrogate keys are unique identifiers used in data warehouses to replace primary keys from source systems. They protect against changes to source systems, allow integration from multiple sources, enable rows that do not exist in sources, track changes over time such as new customer records for address changes, replace text keys with more efficient integers, and provide higher performance than long alphanumeric keys.
Dw design 3_surro_keys
- 1. DATA WAREHOUSING Multi Dimensional Data Modeling. Surrogate Keys.
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- 4. ï‚¡ A surrogate key is a unique identifier for data warehouse records that replaces source primary keys (business/natural keys) 4
- 5. ï‚¡ Protect against changes in source systems 5
- 6. ï‚¡ Allow integration from multiple sources 6
- 7. ï‚¡ Enable rows that do not exist in source data 7
- 8. ï‚¡ Track changes over time (e.g. new customer instances when addresses change) 8
- 9. ï‚¡ Replace text keys with integers for efficiency 9
- 10. ï‚¡ Higher performance with numeric keys than with long, alphanumeric keys 10
- 11. ï‚¡ The Data Warehouse Toolkit.Second Edition.The Complete Guide to Dimensional Modeling.Ralph Kimball.Margy Ross