Activating bidirectional cross-filter in a Tabular data model might create ambiguous paths in the chain of relationships, resulting in very dangerous models as numbers become unpredictable. This article provides a deep explanation of the kind of ambiguity that might appear…  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

This article describes how to use the detail rows expression of a measure to obtain the equivalent of creating table functions in DAX. This allows the reusing of a table expression in multiple CALCULATE filters.  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 describes a very common optimization pattern that relies on variables to optimize conditional expressions in DAX.  Read more

The Sort By Column feature in Power BI causes side effects that are important to know when writing a DAX formula. This article explains these side effects and how to write correct DAX code to avoid getting incorrect results.  Read more

In budgeting reports, a common requirement is to show future sales forecast and actual sales volume on the same line chart. This article describes how to achieve this goal using DAX.  Read more

Estimating the cardinality of iterators is an important skill when optimizing DAX code. This article explains how to use this technique, evaluating different ways of computing the number of working days between two dates.  Read more

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

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