Power BI was created for the lightning speed of reports. Nevertheless, knowing how to create efficient datasets and semantic models is still good. You will learn how natural and even artificial hierarchies can help guide end users to create efficient reports. It is quite important how you write DAX formulas for complex measures. You probably heard about query folding, a capability of Power Query to push processing down to the source as much as possible. Does it always give you the best possible performance? What about data science analysis optimization? You cannot process billions of rows with advanced visualizations, including R and Python visuals. You can help yourself with data sampling. Once the data model is optimized, you can also do a lot on the reports side. In Power BI Desktop, you even have the Performance Analyzer tool that helps you with this task. You learn also how to use aggregate, dual mode and hybrid tables in Power BI. Parts: •     Optimizing the data model •     Query folding •     Performance of reports •     Aggregate and dual storage tables