This article describes the differences between report-based tools and model-based tools. Because Power BI is a model-based tool and not a report-based tool, it is useful to have a quick reference guide explaining these differences.  Read more

Today we start the preview of Smart Filter Pro. This is the first commercial custom visual produced by OKViz and it will be in preview until the end of 2018.  Read more

This article describes how to optimize DAX expressions with mutually exclusive calculations that might cause slow query performance.  Read more

This article describes a very common optimization pattern that relies on variables to optimize conditional expressions in DAX.  Read more

This article describes the behavior of the COMBINEVALUES function in DAX, and how it can optimize the performance of DirectQuery with multi-column relationships.  Read more

A recurring issue for Power BI users writing DAX code is that column filter removal might have an unexpected behavior when the Sort by Column is active on the column. I covered this topic in an article related to RANKX,…  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

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