DAX supports dates starting in 1900 and while teaching DAX I always explain that DAX manages dates like Excel, which is the reason why these limitations exist. Actually, this is true – but answering to a comment today I realized…  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

DAX has many time intelligence functions that are often redundant, offering different shorter syntaxes for longer more generic functions. However, sometimes the shorter syntax could be dangerous, as I explain in this blog post where I suggest using CALCULATE and…  Read more

This article describes how to use a measure to filter a Power BI visualization, and the different behaviors of a same filter between different visuals.  Read more

In the last few years, the Business Intelligence (BI) world has been moving towards self-service BI. As expected, several vendors created tools empowering regular users to gain insights from their data. Among the many, there is Power BI. Nowadays, users…  Read more

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

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

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. You can start using it today, no registration required, and…  Read more

By answering to a student question I realized we often used a wrong calculation of customers age in DAX, and the simple solution is to borrow the same technique used in Excel, using INT and YEARFRAC rather than DATEDIFF or…  Read more

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