Re: Only reload QVF if condition is met, cancel if not
One approach could be to update another table/variable/parameter after finishing the SSIS to DWH transfer. This parameter could be read from the qvf and if it isn't newer as by the last execution: exit script;
Another way might be to implement an intermediate step which is loading from the DWH and the final load-step from the qvf checked those number of records or the max. timestamp or similar to decide to load the updated data or to cancel this task.