This article describes the differences between eager evaluation and strict evaluation in DAX, empowering you to choose the best evaluation type for your data models.  Read more

This article describes how blank values considered in a DAX conditional expression can affect its query plan and how to apply possible optimizations to improve performance in these cases.  Read more

I often get questions about use cases for Azure Analysis Services. So I wanted to do a quick recap of the points I commonly discuss in these conversations, and have them readily available for the next conversation… As a bonus,…  Read more

This article describes how to analyze the performance of a DAX measure based on a DISTINCTCOUNT calculation and how to evaluate possible optimizations.  Read more

In 2015 I released the first version of VertiPaq Analyzer, a tool to quickly analyze the structure and data distribution of a Tabular model that can be used with Analysis Services and Power BI.  Read more

This article describes how to import into DAX Studio the performance metrics that can be exported by the Power BI Performance Analyzer, simplifying the analysis of slower queries in a report.  Read more

This article describes how to use and interpret the information provided by the Power BI Performance Analyzer, finding the bottlenecks in slow reports.  Read more

Aggregations have been introduced in 2018 in Power BI, as an optimization technique to manage large tables. By providing pre-aggregated tables, you can highly improve the performance of a Tabular data model. In this session we introduce the concept of…  Watch now

This article describes how variables should be used in DAX expressions involving IF and SWITCH statements in order to improve performance.  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