Book Image

Expert Data Modeling with Power BI

By : Soheil Bakhshi
Book Image

Expert Data Modeling with Power BI

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 data models using Power BI confidently. 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. In this book, you'll explore how to use data modeling and navigation techniques to define relationships and create a data model before defining new metrics and performing custom calculations using modeling features. As you advance through the chapters, the book will demonstrate how to create full-fledged data models, enabling you to create efficient data models and simpler DAX code with new data modeling features. With the help of examples, you'll discover how you can solve business challenges by building optimal data models and changing your existing data models to meet evolving business requirements. 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. 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 reporting and data analytics.
Table of Contents (18 chapters)
Section 1: Data Modeling in Power BI
Section 2: Data Preparation in Query Editor
Section 3: Data Modeling
Section 4: Advanced Data Modeling

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; it also improves performance and memory consumption. Summarization is a known technique in data warehousing where we want to change the granularity of a fact table. But in Power Query, there are other cases where we can use the Group By functionality to cleanse data. Nevertheless, from a data modeling point of view, we summarize a table by grouping by some descriptive columns and aggregating the numeric values.

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


The Group By operation changes the table's structure. To keep the Internet Sales table unchanged for the future scenarios in this chapter, we will reference the Internet Sales table and name it Internet Sales Summary. We'll use that table in...