While trying to work out incremental load on a QVD, I ran into the following problem:
First I created a QVD file with all records. Then I do a database read and store the result in a resident table. To concatenate new records into my QVD, I do a where clause on the resident table, finding records which have been added since last QVD creation time.
So, I read the creation time into a variable, like this (and this works fine):