When I started with QlikView (V7), we sometimes wanted to operate on data other than the current selections. We accomplished this with the ALL keyword and complex if() functions. It usually did the job but slow, resource intensive and frequently complex to code.
Along came Set Analysis in QV8.5. Brilliant! Performance problem solved!
We still wanted to do comparative analysis, something not directly supported by Set Analysis. So we resorted to loading fields a second time in a data island. Once again, slow, complex if() functions.
Along came the Alternate States feature in QV11. Brilliant! Performance problem solved!
The Qlik Sense client does not yet support Alternate States. We know the backend QIX engine supports Alternate States, but accessing the feature outside the client is beyond the reach of most QS Developers.
Now going “back to the future”, we see very smart QS developers creating patterns for doing comparative analysis in QS using data islands.
It’s good work. But it’s coding gymnastics. Data islands come at a cost, inflating and complicating the data model and consuming additional server Cache and CPU.
So here is my pitch to the QS Product Team at Qlik: We know that data islands can be a performance pitfall. We’ve seen the problem and the solution in QlikView. Can we skip the “adversity will make you stronger and smarter” phase and just expose Alternate States in the QS Client? Now please?