In almost all of the examples the start point is to have an interval table with a 'From Date' and 'To Date' or a table with a 'Changed Date' so that you can build up a 'From Date' and 'To Date'.
How do you handle cases where you do not have a change date because the source system does not record it?
For example you have a product file that changes product class but there is no last updated date?
On the assumption you cannot change the source system is the done thing to keep a comparison file of the products and product classes for a daily load update and identify the changes, adds and deletes to then build a QVD file with the intervals table showing 'From Date' and 'To Date'? Not got my head round whether or not QlikView can do that yet.
