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

Dealing with SCDs

The term slowly changing dimension, which we usually refer to with its short form, SCD, is a data warehousing concept introduced by the amazing Ralph Kimball. You can learn more about Ralph Kimball here:

The SCD concept deals with moving a specific set of data from one state to another. Imagine we have a human resources (HR) system; Stephen Jiang is a Sales Manager, having 10 sales representatives in his team. The following screenshot shows the sample data for our scenario:

Figure 12.1 – Stephen Jiang is the sales manager of a team of 10 sales representatives

Today, Stephen Jiang has been promoted to Vice President of Sales, so his team grows in size from 10 to 17. The following screenshot shows the changes:

Figure 12.2 – Stephen's team after he was promoted to Vice President of Sales

Another example is when a customer's address changes in...