Improve Power BI performance by optimizing DAX

When you create a Power BI report, you might hit some performance issues when you have a large amount of data, complex data models, or complex DAX expression in your measures. The first goal of this tutorial is to discover possible bottlenecks analyzing the execution of DAX calculations using tools such as DAX Studio and VertiPaq Analyzer. You see how to capture and read essential information from a DAX query plan. With this knowledge, the next step is to evaluate different strategies to improve query performance. During this training, you learn the most common patterns that could have performance issues and possible workarounds to solve them.
The training is delivered as a seminar, and the content is very dense. You can try the same techniques on your notebook during the course, but you should consider getting notes during the seminar and practice later.
The goal is to optimize the report execution and not the refresh time. Thus, this training only considers the performance of DAX expressions and does not cover refresh operation performance related to M code in Query Editor.
The examples are in Power BI, but you can also apply the concept of this training to Power Pivot, Analysis Services Tabular, and Azure Analysis Services.

Feedback link:

Starts: 09:00 9th Mar 2022
Ends: 17:00 9th Mar 2022


Short Description
- Learn how to optimize DAX expressions in a Power BI model to improve query performance.
Should delegates bring a laptop with them?
- A laptop is suggested to execute the same analysis shown by the speaker. It is not mandatory, we do not allocate time for exercises, if an attendee prefers to write notes instead of practicing with the same file used in the demo, the laptop is not necessary.
If so what Spec?
- Same requirement as Power BI Desktop. Suggested 8GB RAM and Windows 10 or Windows 11.
What software and licences do they need?
- Power BI Desktop (free) DAX Studio (free)
What is the structure of the day?
- (draft proposal, subject to small changes before final version) How to locate bottlenecks in Power BI reports (Performance Analyzer, DAX Studio) - identify the slowest visual and the slowest measure. Collect information about the data model using VertiPaq Analyzer Overview of the query plan - introduce formula engine and storage engine Analysis of Server Timings and xmSQL queries. Identify materialization and FE CPU consumption. Analyze and improve common performance issues: excessive materialization, nested iterators, inefficient relationships, high consumption in CallbackDataID, high number of storage engine requests, large cardinality iterators.
What internet requirements do the delegates have?
- No internet required if they already installed the software required and downloaded the sample file for the training day in advance. If they have internet connection, I can provide a QR code to download the sample files used during the day.
What will the delegates get out of the day?
- You will be able to isolate the slowest measures in a report, reproduce the performance issue in a smaller query that can be executed in DAX Studio. You will also know optimization techniques to rewrite DAX expressions that are too slow.
Other technologies
- Azure Analysis Services

Slidedeck Link

Improve Power BI performance by optimizing DAX.pdf


Marco Russo


AzureOn PremisesIntelligence and AnalyticsVisualising and Actioning DataDevelopingOptimisingPower BIAdvancedHow

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