In the previous chapters, we looked at how to create a definition of which data to load. But we did not look at which considerations you should make on how to load and link different tables.
So, in this chapter, we will discuss the following topics:
- Data modeling
- How a data model reflects business processes
The QIX engine is the core of the logic in Qlik Sense. All evaluations and calculations are made by this engine.
Every user selection implies a new logical situation. Other field values than the ones used earlier are possible; summations need to be made, so the charts and the KPIs get different values than what we had before. Everything needs to be recalculated, and the data model defines how this is done.
When the user makes a selection, Qlik Sense first evaluates which field values of other fields are possible and which rows are possible. In this evaluation, the key fields are used to propagate the selection to other tables. This is the logical inference. The second step is to calculate all formulas based on the possible rows. In this step, all aggregations are made.
The data model defines how the QIX engine's logical inference and calculations will be made.