Book Image

Expert Data Modeling with Power BI - Second Edition

By : Soheil Bakhshi
4 (1)
Book Image

Expert Data Modeling with Power BI - Second Edition

4 (1)
By: Soheil Bakhshi

Overview of this book

This book is a comprehensive guide to understanding the ins and outs of data modeling and how to create full-fledged data models using Power BI confidently. In this new, fully updated edition, you'll learn how to connect data from multiple sources, understand data, define and manage relationships between data, and shape data models to gain deep and detailed insights about your organization. As you advance through the chapters, the book will demonstrate how to prepare efficient data models in the Power Query Editor and use simpler DAX code with new data modeling features. You'll explore how to use the various data modeling and navigation techniques and perform custom calculations using the modeling features with the help of real-world examples. Finally, you'll learn how to use some new and advanced modeling features to enhance your data models to carry out a wide variety of complex tasks. Additionally, you'll learn valuable best practices and explore common data modeling complications and the solutions to supercharge the process of creating a data model in Power BI and build better-performing data models. By the end of this Power BI book, you'll have gained the skills you need to structure data coming from multiple sources in different ways to create optimized data models that support high-performing reports and data analytics.
Table of Contents (22 chapters)
1
Section I: Data Modeling in Power BI
4
Section II: Data Preparation in Query Editor
10
Section III: Data Modeling
13
Section IV: Advanced Data Modeling
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...