SQLBits 2019

DAX Gotchas

The FILTER function does not create a new filter context but a row context. The ROW function is executed in a filter context without creating a row context. To demystify this and all the other DAX Gotchas that I bumped into is the goal of my session.

DAX is a very powerful and expressive language, but during my journey of learning it, I discovered several quirks that took me awhile to get my head around.

For example, the FILTER function does not create a new filter context but a row context. The ROW function is executed in a filter context without creating a row context. How does that make sense?

And then we have that CALCULATE function. First you guess that you need it to put it around your SUM and AVERAGE functions in order to perform those aggregations. Then you realize that it does not do anything! But is this then always true?

To demystify these and all the other DAX Gotchas that I bumped into is the goal of this session.

Once you have killed them all, then you will start to live life to the DAX!