Phil Seamark has a performance tuning tip for DAX:
I wrote an article about an optimisation called DAX Fusion that attempts to fuse similar SE calls when it can. This article highlights an elegant DAX-based trick that works for a specific scenario by reducing the number of SE calls that doesn’t rely on DAX fusion. The difference between 1-Column fusion and the other is:
– DAX fusion in the engine works across multiple columns that have the same effective WHERE clause
– 1-Column fusion works by fusing multiple measures that all reference a single column, but with different WHERE clauses
Read on to learn how to switch around a bit of DAX to reduce the number of storage engine calls, as well as an example of one scenario in which it can come in handy.