Tuesday, 30 April 2013

SCD Type 6: Add Type 1 Attributes to Type 2 Dimension


Type 6 builds on the type 2 technique by also embedding current attributes in the dimension so that fact rows can be filtered or grouped by either the type 2 value in effect when the measurement occurred or the attribute’s current value. The type 6 moniker was suggested by an HP engineer in 2000 because it’s a type 2 row with a type 3 column that’s overwritten as a type 1; both 2 + 3 + 1 and 2 x 3 x 1 equal 6. With this approach, the current attributes are updated on all prior type 2 rows associated with a particular durable key, as illustrated by the following sample rows:



 

Implementation part will come later.

Hope this helps.

Feel free to leave your comments.

No comments:

Post a Comment