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DAX Course Review Questions

Answer these questions. When the questsion ask for examples, show example DAX code from the case study that we have used in the course.

1. What three types of objects can be created by a DAX expression? When would you use each type? – give examples
2. What is the difference between aggregator and iterator functions? Give examples. When might you use an iterator rather than the corresponding aggregator?
3. What is the difference between scalar and table functions? Give examples
4. How does a calculated column differ from a measure? Give examples.
5. What alternatives are there to implementing a calculated column in DAX?
6. What alternatives are there to implementing a measure in DAX?
7. What is an explicit measure? Which calculations are explicit measures? Why are they considered good practice?
8. What is filter context? And row context?
9. Explain briefly what these important DAX functions do
   • CALCULATE()
   • ALL()
   • FILTER()
   • KEEPFILTERS()
10. Why use variables in DAX?
11. Why are table functions sometimes useful in measures (which can only return a scalar value) Give examples?