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

Working with Group By

One of the most valuable and advanced techniques in data modeling is creating summary tables. In many scenarios, using this method is very beneficial. We can use this method to manage our Power BI file’s size and improve performance and memory consumption. Summarization is a known technique in data warehousing where we change the granularity of a fact table to a higher grain. But in Power Query, there are other cases where we can use the Group By functionality to cleanse the data. From a data modeling point of view, we summarize a table by grouping it into descriptive columns and aggregating the numeric values.

Let us go through a scenario and see how the Group By functionality works.

In this section, we use the Chapter 5, Common Data Preparation Steps, Fixed OrderDateTime Data Type.pbix sample file that we created before. You can download the file from here:

https://github.com/PacktPublishing/Expert-Data-Modeling-with-Power-BI-Second-Edition...