Adding New Column to a Type 2 dimension
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Adding New Column to a Type 2 dimension
Hi,
There are too much papers about Slowly Changing Dimensions saying SCDs have to grow up slowly, telling about design practices to avoid rapidly changing scenarios like mini dimension usage, junk dimension usage etc..
But there is a very big problem when a new attribute has to be added to an existing type 2 dimension. It means adding null columns to existing records then a day later adding a new verison for all current records. If I have 10.000 distinct customers in my customer dimension and I add a new attribute to this dimension, following day I will add 10.000 more records to it.
Dou you have any recommendation or a design tip on this scenario?
Thanks in advance.
There are too much papers about Slowly Changing Dimensions saying SCDs have to grow up slowly, telling about design practices to avoid rapidly changing scenarios like mini dimension usage, junk dimension usage etc..
But there is a very big problem when a new attribute has to be added to an existing type 2 dimension. It means adding null columns to existing records then a day later adding a new verison for all current records. If I have 10.000 distinct customers in my customer dimension and I add a new attribute to this dimension, following day I will add 10.000 more records to it.
Dou you have any recommendation or a design tip on this scenario?
Thanks in advance.
umutiscan- Posts : 51
Join date : 2010-11-26
Age : 44
Location : Istanbul, Turkey
Re: Adding New Column to a Type 2 dimension
There is no reason you cannot set the current value of the column in the current version of the type 2 member. You don't need to create all new rows. You can also populate the same value in all historical versions if the users are ok with it.
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