I have a fairly large & wide table (~2 million rows) and I have 7 different look up tables for it. I created a qvd which uses apply map to look up all these values so I am storing male/ female instead of 1/2 and so on. Does any one know how will it compare to a qvd which stores 1/2 and joins with look up in my qvf data model?
The size of the QVDs with and without look up will be pretty close the same, as Qlik implement a clever way to save the data that optimize QVDs size. You can test this concept by saving the QVDs with and without the look up.
You data model will be smaller, with less tables in it, that will be benefitial when we are talking about gender and alike, it will be easier to understand.
I haven't notice any performance impact, and it could reduce your memory usage as well.