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

Be mindful of query folding and its impact on data refresh

Data modelers need to pay extra attention to query folding. Not only can query folding affect the performance of a data refresh but it can also hit resource utilization during the data refresh. Query folding is essential for the very same reason an incremental data refresh is, so if the refresh takes too long due to the queries not being folded, the incremental data refresh never happens. It is also crucial for the models in either DirectQuery or Dual storage mode as each transformation step must be folded. As query folding is a vital topic, it is good to spend some time to see what it is all about.

Understanding query folding

Query folding is simply the Power Query engine’s capability to translate the transformation steps into the native query language. Therefore, based on the Power Query engine’s capability, a query in the Power Query Editor may be fully folded or partially folded. For instance, we...