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

This article introduces a technique to filter and productively compare two time periods with Power BI.  Read more

This article explains how DAX handles dependencies between tables, columns and relationships, to help you avoid circular dependency errors.  Read more

This article explains how to use KEEPFILTERS to intersect instead of overriding an existing filter context in DAX, simplifying the code and improving performance.  Read more

This article compares the differences between calculated columns and calculated tables from a processing and storage point of view.  Read more

This article describes how to create a table with a series of numbers in DAX by using the new GENERATESERIES function or through a workaround using CALENDAR.  Read more