The biggest news as far as I can see about SSAS 2019 is Calculation Groups. This is the long awaited feature, define calculated measures, used by many in Multidimensional Cubes. The new ‘table’ contains the Time intelligence (among other calculation types) for creating the calculation once, like MTD, and using it on multiple existing measures. I have seen the pains of this in large Tabular Models I have worked with.

Here is an example of the DAX

MTD – CALCULATE( SELECTEDMEASURE(),  DATESMTD( DimOrderDate[DateKey] ) )

There is another item called Sideway calculations which looks simple but you need an understanding of what is going on.

Additional there is a Precedence property to set the sequence of the calculations.

There are some new DAX functions like SELECTEDMEASURE and SELECTEDMEASURENAME. Returns the measure in context and the string name as well as a ISSELECTEDMEASURE Boolean function.

Additional new features:

1. 2 new DMV functions

2. Object level Security on new Calculated Groups

3. Dynamic formatted strings

Not yet seen, but listed is some MDX query support and Row level Security.