In the previous section, we have stored data into QVDs. Now it is time to read or load from a QVD. QVDs can be read as a regular load or as an optimized load.
An optimized load is a super-fast load that occurs if no transformations occur or certain conditions are applied. An optimized load is indicated by the message in the script progress window.
The following conditions apply to an optimized load:
Where Exists(EmpID,SalesID)is not allowed.