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

If you import more than one table into Power BI or Power Pivot, you have a data model. When you have more than one table, you usually have relationships between tables. When you analyze data, you often have many choices…  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

We are approaching the end of 2017, so it is a good time to review what happened in the DAX world this year, what we’ve been up to at SQLBI and what is going to happen in 2018. New DAX…  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

During a conversation at PASS Summit, one of the developers of Power BI shown me a way to use TREATAS in place of IN in DAX. I am not sure it increases readability of the code, but let’s examine pros…  Read more

I recently stumbled across a strange behavior of HASONEVALUE, which also impacts the SELECTEDVALUE function. When the only selected item in a column is a numeric value 0 and the column also contains a blank value, there is a bug…  Read more