Performance Problems with IF statement execution in SSAS Tabular
Due to the high compression rates and stellar in-memory architecture of SSAS Tabular, most people with smaller models do not experience performance problems (in-spite of employing bad data modeling techniques and inefficient DAX measures). However, as the size of your models increase, you will start to see performance issues creep up, especially if you are not paying attention to data modeling and DAX measures. Last week, I gave a presentation at the PASS Summit 2015 on my experience of building a 150 GB Tabular model in SSAS 2012. During that, I shared my story on how some of the DAX measures with IF statements were causing performance issues and how to work-around that issue by rewriting your DAX measures. During that day, Microsoft also announced that they resolved this issue in SQL 2016, so I thought of demonstrating the issue, workaround and also the fix in SSAS 2016.
Tags: performance, dax, tabular