Non-chronological loads and SCD Type 2

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Non-chronological loads and SCD Type 2

Post  manimal on Mon Feb 15, 2010 2:38 pm

Does the notion of loading a data mart in a non-chronological fashion conflict with supporting SCD Type 2?

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Re: Non-chronological loads and SCD Type 2

Post  BoxesAndLines on Tue Feb 16, 2010 11:32 pm

You'll need two sets of dates for your dimensions. The EDW insert date and end date as well as business effective and end dates. I don't see why it wouldn't work. You'll need to include date on all your dimension lookups to make sure it works right since the most current row might actually be older the previous historical row.

Tom Johnston co-wrote a great set of articles on Information Management that goes into great detail on how to manage history in relational databases. You'll need to adapt it to dimensional models.
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Re: Non-chronological loads and SCD Type 2

Post  manimal on Thu Feb 18, 2010 4:40 am

thank you first of all for your response.

i understand "business effective and end dates" right away. these dates simply represent the span of time for which some detailed description was valid. and in this context, your comment regarding dimension lookups is also very clear. however, the purpose served by the "EDW insert and end dates" is not immediately obvious to me. can you elaborate? thank you again for your time.

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Re: Non-chronological loads and SCD Type 2

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