Delta extraction based on "High Water" fields

[#1]

Hello all,

I'm new to QlikView, using QlikView with SAP and SAP BW. We have a large amount of data, and need to performe incremental loads.

In performing QlikView extractions, can QlikView perform a delta or incremental extact using a field like a document number or timestamp as 'high water mark' - storing the maximum value from the previous extraction, and using 'greater than' logic to select records greater than the last extraction's highest value.

High water mark, delta, or incremental extraction have been standard features in ETL tools for 15 years, but I can not find information on how to do this in QlikView!

Please send hyperlinks and sample code!

Thanks,

John Hawk

[johnw]

Look for "incremental load" in the reference manual. It appears to have decent explanations, graphics, and example script. It isn't strictly how I'd do it, in that I wouldn't store the last execution time in a variable, but instead load the maximum timestamp from the QVD. Same general idea, though.

There is also an example incremental load in Rob Wunderlich's QlikView cookbook:

http://robwunderlich.com/Download.html