One type of fact table in Dimensional modeling is
Accumulating Snapshot fact Table. if you think you need to review the meaning and definition of this type , you can take a look at this article :
Imagine we have an accumulating fact table which has three important date column in it
'Order_Datekey , Manufacturing_Datekey , Ship_Datekey'
When the table is being inserted for the first time ,there is no data for columns
Manufacturing_Datekey and Ship_Datekey'. We only know the date in which the product has been ordered (Order_date). What I need to know is that how we can handle null values for Date columns ?
The important point I read in Kimbal book is that null should be avoided in a foreign key column.
'Referential integrity is violated if you put a null in a fact table column declared as a foreign key to a dimension table'
On the other hand we don't have any value for these two date columns at first. What do you suggest?
Thanks in advance