Help with incremental loads or deltas

[#1]

What is the best way to set up a QVD to only load deltas?

[#2]

you can do it using the script. you need to identify field to check on the existing data and the new data.

Eg: if you are checking month field. write a script to load only those months which are not in the QVD.

[stigchel]

There are sevral examples of incremental loads in the community, I've got this example from Rob Wunderlich. Take a look and see if it helps...