This article describes how to implement in DAX a logical OR condition between the selection of two slicers of a Power BI report or of a PivotTable in Excel. By default, when relying on more than one slicer they are…  Read more

Expanded tables are the core of DAX; understanding how they work is of paramount importance. This article provides a theoretical foundation of what expanded tables are, along with fundamental concepts useful when reading DAX code.  Read more

This article describes how to use DAX Studio to capture DAX queries generated by Power BI. Analyzing DAX queries can be helpful to better understand performance issues, and to improve the writing of DAX queries.  Read more

This article provides a complete explanation of the behavior of the ALLxxx functions in DAX. When used as filters in CALCULATE, ALLxxx functions might display unexpected behaviors.  Read more

This article describes a reference Date table in DAX using a Power BI template. The same technique can be used in Analysis Services models. Download the latest version of the template in the Dax Date Template page.  Read more

ALLSELECTED is a powerful function that can hide several traps. This article is an in-depth analysis of the behavior of ALLSELECTED, explaining shadow filter contexts, what they are and how they are used by ALLSELECTED.  Read more

This article describes how to use variables to optimize the performance of DAX expressions containing multiple instances of the same measure or the same sub-expression.  Read more

This article explains how the context transition interacts with the filter arguments of a CALCULATE function in DAX. This is important in order to avoid unexpected results with complex calculations made in filter arguments.  Read more

This article shows a technique in DAX to compute the sales volume of products that were available right from the beginning of a selected time period, ignoring products introduced afterwards.  Read more

This article describes a counterintuitive behavior of BLANK in DAX measures affecting Power BI, Analysis Services, and Power Pivot. That behavior could cause mistakes in a report using alternate expressions of the same calculation. Indeed, these expressions are not equivalent…  Read more