Does Power BI calculate all variables or only the ones it uses in the return ?

[Anonymous]

I just want to understand how Power BI and SSAS logic works.

Let's say we have a measure that does the following : 

Test Measure = 

Var Test1 = sum(sales)

Var Test2 = sum(quantity)

RETURN Test2/365

Will it also calculate the variable Test1 in the background or will it only calculate Test2 ?

Thanks in advance

[FreemanZ · Accepted solution]

Only test2. It is called lazy evaluation: a variable is evaluated only when first used, but in the context of definition.