Implementing Slowly Changing Dimensions (SCD) using ODI
If the reader is familiar with the fundamentals of data warehouse design, there should already be an understanding of three basic forms of dimension management:
- Type-I: No historical data (new record data replaces the old data)
- Type-II: Complete historical data (with start and end date bracketing)
- Type-III: Limited historical data (only the most recent data is kept)
There are other SCD methods (that is history tables, hybrids, and so on) not mentioned, but due to the infrequency of their use or lack of support by ODI, they have been omitted from this discussion. It is not within the scope of this book to discuss the advantages, disadvantages, and reasons for using any of these SCD formats, ...