Difference between what-if parameters and DAX table?

[CliffordAP]

Hello all,

I am looking into ways to have user input for some reports I am making. My first idea was to make dedicated tables that store values for the user to select (like categories, or numbers). On the report level we can make Dax logic for calculations based on the informaiton the user selects from these tables.

Then I looked into What-if parameters. I saw 1 example, and I feel like they do the same thing. Defines a table with a set of values defined by what you specify when creating the What-if Parameter.

Is there a difference between using what-if parameters and defining DAX tables in the model?

[v-easonf-msft · Accepted solution]

Hi, @CliffordAP 

When you create and use 'what-if parameters'  to visualize variables in Power BI Desktop, it will generate a slicer, a measure, and a Dax table based on "GENERATESERIES" function.

The different from the ordinary Dax table is that it returns a single column table containing the values of an arithmetic series, that is, a sequence of values in which each differs from the preceding by a constant quantity.

For more details, you can refer to the demo provided in the official document.
https://docs.microsoft.com/en-us/power-bi/transform-model/desktop-what-if 

Best Regards,
Community Support Team _ Eason

[YukiK]

I don't think there is much difference in each mechanics, but when creating a what-if parameter, it comes with a selectedmeasure. That's the only difference I see.