Book Image

Extreme DAX

By : Michiel Rozema, Henk Vlootman
Book Image

Extreme DAX

By: Michiel Rozema, Henk Vlootman

Overview of this book

This book helps business analysts generate powerful and sophisticated analyses from their data using DAX and get the most out of Microsoft Business Intelligence tools. Extreme DAX will first teach you the principles of business intelligence, good model design, and how DAX fits into it all. Then, you’ll launch into detailed examples of DAX in real-world business scenarios such as inventory calculations, forecasting, intercompany business, and data security. At each step, senior DAX experts will walk you through the subtleties involved in working with Power BI models and common mistakes to look out for as you build advanced data aggregations. You’ll deepen your understanding of DAX functions, filters, and measures, and how and when they can be used to derive effective insights. You’ll also be provided with PBIX files for each chapter, so that you can follow along and explore in your own time.
Table of Contents (17 chapters)
Free Chapter
1
Part I: Introduction
6
Part II: Business cases
15
Other Books You May Enjoy
16
Index

Data types and encoding

The Power BI model works with a limited number of data types. Choosing the right data type for your data is important, as it determines the way your data is stored, or encoded, and how efficiently the model can process your data. Below is a list of all the data types recognized by Power BI:

  • Text: The most generic data type is Text. Virtually all data can be stored as Text. When loading data through Power Query, the generic Power Query data type Any is converted to Text in the Power BI model. This causes numerical columns to be stored as Text when you forget to explicitly make the type conversion in Power Query. (You can, of course, change the data type in the model, which will automatically add a type change step in Power Query.)
  • Whole Number: The data type Whole Number is used, as you would guess, to store whole numbers. Because of the way the Power BI model stores and compresses data, this is one of the most efficient data types available...