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Author: Kevin Feasel

Default Frames in Window Functions

Published 2026-01-02 by Kevin Feasel

Hugo Kornelis has gotten into the video game:

Below, you find my first video blog. I talk about the OVER clause, and I hope to convince you why you should always explicitly specify the ROWS or RANGE clause – even though that takes a bit more typing.

Understanding what the default frames look like for your queries is important. And it’s important to note that the default frame is different based on whether you use SUM(x) OVER() or SUM(x) OVER(ORDER BY X). It also doesn’t matter for ranking window functions (ROW_NUMBER(), RANK(), DENSE_RANK(), NTILE()) because you’re not allowed to specify a window frame.

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Implementing Tooltips on Dynamic Measures

Published 2026-01-02 by Kevin Feasel

Teo Lachev shows some information:

Happy New Year with oldies but goodies…especially given that this technique might be hard to find elsewhere! How do you implement a tooltip page that shows only the measure the end user hovers over? Consider this matrix with three measures on columns grouped by product categories on rows. The user wants to see a trend chart for the measure they hover over.

I’m trying to remember if this is possible in Power BI Report Server. I don’t want to slander the product unnecessarily (my necessary slander should be good enough, thank you), so I won’t hazard a guess.

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Thoughts on Master Data Services Removal

Published 2026-01-02 by Kevin Feasel

Niko Neugebauer is upset:

I have worked with Master Data Services (aka MDS) extensively, especially during the engagement at OH22 around a decade ago, and I my interest in the area and that specific is documented in my blog – with the following examples: What is wrong with MDS (Master Data Services) Database in SQL Server 2019 & Master Data Services in SQL Server 2019.
In my professional experience (at OH22) I even had to dig into the internal code of the MDS and from my experience the Software Engineers at Microsoft at MDS team I have talked to – knew much less about it than I did.

MDS was launched in SQL Server 2008 R2 and the feature was there with minor changes since SQL Server 2016, with the last update being done in SQL Server 2019. Now, in SQL Server 2025 we have a significant change – Master Data Services are dead. Yes, you read it right – not deprecated and will be removed in the future, not deprecated and unsupported, but – removed.

Read on for a paean to a removed product and commentary on the lack of a viable replacement within Microsoft.

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Diagnosing DirectQuery Connection Limit Issues

Published 2025-12-31 by Kevin Feasel

Chris Webb goes troubleshooting:

To kick off my series on diagnosing Power BI performance problems with Performance Analyzer in the browser (which I introduced last week with my post on vide-coding a custom visual to visualise Performance Analyzer data), I want to revisit a subject I blogged about two years ago: how hitting the limit on the maximum number of connections to a DirectQuery data source can lead to queries queuing for an available connection and performance problems. In my original post on this topic I showed how you can use the Execution Metrics event in Profiler/Log Analytics/Workspace Monitoring to see when this queuing happens. In this post I will show how you can do exactly the same thing with Performance Analyzer.

Read on to learn how.

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Python Libraries for Advanced Time Series Forecasting

Published 2025-12-31 by Kevin Feasel

Ivan Palomares Carrascosa has a list:

Fortunately, Python’s ecosystem has evolved to meet this demand. The landscape has shifted from purely statistical packages to a rich array of libraries that integrate deep learning, machine learning pipelines, and classical econometrics. But with so many options, choosing the right framework can be overwhelming.

This article cuts through the noise to focus on 5 powerhouse Python libraries designed specifically for advanced time series forecasting. We move beyond the basics to explore tools capable of handling high-dimensional data, complex seasonality, and exogenous variables. For each library, we provide a high-level overview of its standout features and a concise “Hello World” code snippet to familiarize yourself immediately.

Click through for an explanation of each of the five libraries.

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The Year in DAX 2025

Published 2025-12-31 by Kevin Feasel

Marco Russo lays out a list:

This was a big year for DAX, with the public preview that started in September for two new features: user-defined functions (UDFs) and calendar-based time intelligence.

The user-defined functions are the most significant update to the DAX language since 2015, when Microsoft introduced variables. Can you believe that for more than five years we had to write DAX code without variables? Well, the user-defined functions we just mentioned will have an even bigger impact in the long term.

Read on for more information on key additions, new DAX functions, and all of the neat stuff that the SQLBI team put together this year.

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Object-Level Security in Power BI

Published 2025-12-31 by Kevin Feasel

Vin Mai Quang lays out an explanation:

For a POC project, my team lead asked me to practice and build a demo Power BI report that applied OLS (Object Level Security). Although it sounded simple at first, I was surprised by how OLS actually behaves in Power BI. In this blog, I would like to share my findings with you.

Click through for a demonstration of how it all works, including how to deal with scenarios in which customers shouldn’t get access to specific columns but should still be able to see others.

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Tracking Database File Sizes via Powershell

Published 2025-12-31 by Kevin Feasel

Kyle Burwell wants to know how big the databases are:

Database files (mdf, nds, ldfs, etc.) can get out of hand quickly and easily, leading to issues down the road. This can be due to improper planning, large data loads, and bad code run in production, just to list a few. As unglamorous as disk space monitoring is, we need to do our part as DBAs. This post is a quick guide on how to track database file sizes with PowerShell.

Read on for a few scripts to perform the task.

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Creating a SQL Server 2025 Practice Environment

Published 2025-12-31 by Kevin Feasel

John Deardurff installs SQL Server 2025:

Microsoft SQL Server 2025 introduces major advancements in performance, security, and built‑in AI capabilities. Before you can start exploring its new features, you need to install it correctly. This guide walks you through the full installation process of SQL Server 2025, SQL Server Management Studio 22, and restoring the AdventureWorks2025 database to create a practice environment to test the new features and enhancements of this new release.

I was going to joke, “But John, what about your loyal Linux-using readers? How can we do this?” But instead, I’ll say that I’m glad that AdventureWorks is still alive and kicking. It is, on the whole, a nice demo database.

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Top Microsoft Fabric Features from 2025

Published 2025-12-30 by Kevin Feasel

Nikola Ilic builds an end of year list:

Microsoft Fabric just turned two a couple of weeks ago (at Ignite in November, to be more precise). As the product is still very much a “work in progress”, we have overseen literally hundreds of new features in the last 365 days. Obviously, not all of them are equally important – some were simply trying to fix the obvious issues in the existing workloads, or trying to catch up either with competitors or with some functionalities we had in the older Microsoft data platform solutions, whereas the others were targeting super niche use cases.

Therefore, in this article, I’ll try to distill what I consider the biggest announcements around Microsoft Fabric in 2025.

Read on for three caveats, followed by the list and quite a few additional nominees.

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