This article describes how blank values considered in a DAX conditional expression can affect its query plan and how to apply possible optimizations to improve performance in these cases.  Read more

Creating a star schema in Power BI is the best practice to improve performance and more importantly, to ensure accurate results! This article shows why a star schema can fix some of the issues in your report.  Read more

This article provides information to help choose between DAX and Power Query when a table needs to compute additional columns.  Read more

This article describes how to analyze the performance of a DAX measure based on a DISTINCTCOUNT calculation and how to evaluate possible optimizations.  Read more

This article shows how to add an additional “other” row to the selection obtained using the Top N filter in a Power BI report.  Read more

This article describes what weak relationships are and the differences between strong and weak relationship in Power BI and DAX.  Read more

In 2015 I released the first version of VertiPaq Analyzer, a tool to quickly analyze the structure and data distribution of a Tabular model that can be used with Analysis Services and Power BI.  Read more

This article describes how to compute previous year values up to a certain date. This is useful in case the data is presenting incomplete months or years.  Read more

This article describes how to create a slicer showing the values of multiple columns, applying the filter on any of the underlying columns.  Read more

The second edition of The Definitive Guide to DAX is now available worldwide! This blog post explains why we felt the need to rewrite the book and describes what happens behind the scenes when producing a book.  Read more