DAX vs MDX

[claudiassmatos7]

What are the advantages and disadvantages of using DAX instead of MDX in SSRS (with tabular cubes)?

[claudiassmatos7]

Thank you!

[d_gosbell · Accepted solution]

There are no real disadvantages to using DAX against a tabular model. DAX is the native expression language for tabular models. But there are a couple of disadvantages to using MDX

1. MDX has different semantics, so there are extra steps that need to be done when a tabular model evaluates an MDX query that are not needed when evaluating DAX - resulting in slower performance
2. MDX returns multi-dimensional cellsets which have to go through a process called flattening to be consumed by SSRS which also adds extra overhead.