You're reading from Expert Data Modeling with Power BI, Second Edition Enrich and optimize your data models to get the best out of Power BI for reporting and business needs

Product type Paperback

Published in Apr 2023

Publisher Packt

ISBN-13 9781803246246

Length 698 pages

Edition 2nd Edition

Languages

DAX

Tools

Power BI

Concepts

Business Intelligence

Author (1):

Soheil Bakhshi

View More author details

Table of Contents (22) Chapters

Preface

1. Section I: Data Modeling in Power BI

2. Introduction to Data Modeling in Power BI FREE CHAPTER

3. Data Analysis eXpressions and Data Modeling

4. Section II: Data Preparation in Query Editor

5. Data Preparation in Power Query Editor

6. Getting Data from Various Sources

7. Common Data Preparation Steps

8. Star Schema Preparation in Power Query Editor

9. Data Preparation Common Best Practices

10. Section III: Data Modeling

11. Data Modeling Components

12. Star Schema and Data Modeling Common Best Practices

13. Section IV: Advanced Data Modeling

14. Advanced Data Modeling Techniques

15. Row-Level and Object-Level Security

16. Dealing with More Advanced Data Warehousing Concepts in Power BI

17. Introduction to Dataflows

18. DirectQuery Connections to Power BI Datasets and Analysis Services in Composite Models

19. New Options, Features, and DAX Functions

20. Other Books You May Enjoy

21. Index

Understanding virtual tables

The concept of virtual tables in DAX is somewhat confusing and misunderstood, yet it is one of the most powerful and important concepts in DAX. When we talk about virtual tables, we refer to in-memory tables that we build using certain DAX functions or constructors. The data in a virtual table is either derived from the data within the data model or the data we construct for specific purposes.

Remember, whenever we use a DAX function that results in a table of values, we are creating a virtual table.

At this point, you may ask, so when I use a DAX function to create a calculated table, am I creating a virtual table? The answer is it depends. If you simply use a set of DAX functions that generate data or selectively load data from other tables into a calculated table, the answer is no: you have not created any virtual tables.

Nevertheless, when generating or loading the data from other tables, taking some table operations, and loading the results...