Introducing SCD's

[Chicken Head]

At the moment we currently have a data warehouse which i've developed from scratch myself, it isn't huge and fairly simple but still follows the whole star schema setup with conformed dimensions etc. My current skills set is pretty basic as I had to basically learn everything from scratch myself, this was due to a failed project which the business won't spend any futher cash on and lack of knowledge transfer from the consultants at the time, so basically I'm learning as I build.

All of the data that comes in at present is fully refreshed i.e all of the fact tables are truncated and full refreshes are performed on the dimensions, however i'm looking to introduce SCD's to the warehouse and was wondering how the treat the fact and dimension tables when doing so. When I was shown on the DS course it concentrates on setting up the dimensions which tracking and using effective start and end dates, current indictators etc. I was wondering how the fact tables will have to be setup, obviously they will have to be changed from truncate to update/insert but I was wondering whether they will need start /end dates too as well as current incitators just like the dimension tables? Also when you are delivering the reports via Cognos 8 RS how does it know which fact to use that is the case.

Apologies if this sounds a bit garbled but any help directed my way will be greatly appreciated.

[Opher]

Well, where to start.  I suggest you get the best book on the subject "The Data Warehouse ETL Toolkit" by Ralph Kimball and read every word.  Your question indicates you have not learned the basic elements of SCD implementation.  Kimball also has a library of design tips at his website (www.kimballgroup.com) which would be good reading.  I suspect you'll have more questions, but they will be better ones <S>.

Good luck,
Opher