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

Avoiding calculated columns when possible

Creating calculated columns is one of the most essential and powerful features of DAX. Calculated columns, as the name suggests, are computed based on a formula; therefore, the calculated column values are unavailable in the source systems or the Power Query layer. The values of the calculated columns are computed during the data refresh and then stored in memory. It is important to note that the calculated columns reside in memory unless we unload the whole data model from memory, which in Power BI means when we close the file in Power BI Desktop or switch to other content in the Power BI Service. Calculated columns, after creation, are just like any other columns, so we can use them in other calculated columns, measures, calculated tables, or for filtering the visualization layer.

A common approach of developers is to use calculated columns to divide complex equations into smaller chunks. That is why we suggest avoiding the excessive...