DAX Performance

Bill Anton reminds me that I don’t know a thing about DAX:

As you can see, using DAX variables is a much better solution than using the aliases…the performance improvement is about the same, however, variables we can wrapped up in the calculated measures inside the model allowing us to take advantage of the performance gain with all tools (not just those allowing us to hand-craft the DAX queries).

The query used in this post is too simple to highlight the performance benefit (small data dataset, simple calculation)…but it did make it easier to cruise the query plans and SE requests. In reality, a better use case for highlighting the performance benefits of these optimizations is with a query that hammers the Formula Engine (FE).

Interesting stuff, even for someone with no knowledge of DAX.

Related Posts

Hiding Work: The Nested Loop Operator

Erik Darling explains that the nested loop operator is like a duck: there’s more going on beneath the surface than it lets on: I’m going to talk about my favorite example, because it can cause a lot of confusion, and can hide a lot of the work it’s doing behind what appears to be a […]

Read More

Hiding Future Dates In DAX Measures

Marco Russo shows how we can define year-to-date measures which don’t include values for incomplete months: The rows between September 2009 and December 2009 should not be visible. The goal here is to display a blank value in these out-of-range, “future” months.A similar issue exists for the year-over-year calculation (YOY). Even though the measure tries […]

Read More

Categories

November 2015
MTWTFSS
« Jan Dec »
 1
2345678
9101112131415
16171819202122
23242526272829
30