August 2019
Intermediate to advanced
768 pages
26h
English
book
Definitive Guide to DAX, The: Business intelligence for Microsoft Power BI, SQL Server Analysis Services, and Excel, 2nd Edition
by Alberto Ferrari, Marco Russo
Content preview from Definitive Guide to DAX, The: Business intelligence for Microsoft Power BI, SQL Server Analysis Services, and Excel, 2nd Edition
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
Start your free trial
Chapter 17The DAX engines
The goal of the book up to this point has been to provide a solid understanding of the DAX language. On top of gaining further experience through practice, the next goal for you is to write efficient DAX and not just DAX that works. Writing efficient DAX requires understanding the internals of the engine. The next chapters aim to provide the essential knowledge to measure and improve DAX code performance.
More specifically, this chapter is dedicated to the internal architecture of the engines running DAX queries. Indeed, a DAX query can run on a model that is stored entirely in memory, or entirely on the original data source, or on a mix of these two options.
Starting from this chapter, we somewhat deviate from DAX ...