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 storage modes

In the previous section, we discussed connection modes for the queries from a Power Query perspective. In this section, we look at different storage modes that apply to tables after the data is loaded into a data model or connected to a data source. Every table in a Power BI data model has a storage mode property that shows if the data is cached or not. There are three types of storage modes, as outlined next:

  • Import: This means the data is cached into the memory. Therefore, all queries over a table with the storage mode of Import get the results from the cashed data.
  • DirectQuery: The data is not cached; therefore, all queries are fired back to the source system to get the results.
  • Dual: The tables in this mode can get data either from the cache or directly from the source system. So, depending on the query, data can be retrieved either from the cached data or directly from the data source. For instance, in an aggregation setup, the query...