My learned friend,
Can someone please enlighten me about difference between slowly shifting grain V/S slowly changing dimension. I am sure they are not same. Grain refers to the lowest level of information stored in a fact is defined. For example for a sales transaction we can say the grain will be what product, which day, which store(location), what customer, what quantity. Can this ever drift or change slowly..?
Slowly changing dimension is I know has three options
option 1 where we simply overwrite the old attribute value with the new value. So no history is maintained.
option2 we insert a new row in dimension
option 3 keep a pair of attributes to preserve the old and new value adding additional columns
BUT WHAT IS SLOWLY CHANGIN OR DRIFTNG GRAIN?