Press "Enter" to skip to content

Curated SQL Posts

Fixing “Too Many Connections” in Postgres

Published 2026-10-28 by Kevin Feasel

Achyut Tripathi makes a connection:

Database connections are essential for any program to manage and access data in the database. When a server already has too many active and open connections – a result of a large number of users creating numerous, simultaneous demands on the system – no new connections can open, and the system indicates that it has reached its maximum connection limit.

This issue can be caused by several factors, including connections that are opened unnecessarily and no longer used by the application, programs that create a large number of connections, incorrectly configured connection pools, and a sudden increase in traffic.

When these issues aren’t managed properly, the system encounters request failures – resulting in no new connections being made.

Read on to see how Postgres handles these and what you can do if you find yourself in that situation.

Leave a Comment

DAX Lib MCP Server

Published 2026-10-28 by Kevin Feasel

Marco Russo makes an announcement:

At the end of 2025, we launched DAX Lib, a public repository of DAX user-defined functions. So far, importing a DAX library has required a few manual steps, like clicking Add to Power BI on daxlib.org and then copying and pasting the DAX code into the TMDL View of your model, or using the dedicated tool in Tabular Editor 3. Both work well, but if you already use an AI assistant next to Power BI Desktop, we can now delegate this task to it. The DAX Lib MCP server version 0.1.0 is available now.

Click through if you’d like to snag a copy. It’s only available for Windows at this point, though considering Power BI’s OS requirements, that makes sense.

Leave a Comment

Reviewing Optimized Locking Results

Published 2026-10-28 by Kevin Feasel

Louis Tochon wants to know if optimized locking actually ran:

In the first case, SQL Server escalated the row locks to an X lock on the whole table. In the second, there is no escalation anymore, only one X lock on the transaction ID (XACT), next to the intent lock (IX) on the table (the IS lock in both results is on the small function I used to run this query).

That is nice in a demo, but on a real server nobody is looking at sys.dm_tran_locks at the right moment. I wanted to know how a DBA can check what optimized locking does once it is enabled. SQL Server 2025 has a few Extended Events for that, and I found some of their fields easy to misread and one of them reports LAQ as enabled on a database where it never ran once.

Click through to learn more.

Leave a Comment

Tips for Planning a Microsoft Fabric Solution

Published 2026-10-28 by Kevin Feasel

Paul Turley shares some tips around the various Microsoft Fabric workloads:

Fabric hands you an entire toolbox of analytics workloads. Using all of them isn’t the goal — using the right ones is.

Resist the shiny-object trap. Fabric packages Power BI, Data Factory, Data Engineering, Data Warehouse, Data Science, and Real-Time Intelligence into one platform, and it’s tempting to adopt all of them at once. Map each workload to a business problem you already have, and bring in only the pieces that solve something real today. Every workload you adopt without a real use case behind it is one more thing your team has to learn, maintain, and eventually explain to an auditor.

Click through for a half-dozen such tips.

Leave a Comment

The SQL Server Execution Plan Reference

Published 2026-10-28 by Kevin Feasel

Hugo Kornelis completes a magnum opus:

In 2017, I made the decision that SQL Server execution plans needed better documentation. I did not expect Microsoft to do this for me. And so I decided, heavily inspired by Paul Randall’s Wait Type Library, to write it myself. I purchased the domain sqlserverfast.com, migrated my blog there, and started to write the SQL Server Execution Plan Reference.

That part of the site went live on May 31, 2018, when I had finished the generic pages plus the pages on all join and aggregation operators. After that, I regularly added a page, sometimes even multiple at once, and I also frequently updated pages with new or corrected information.

Check out the amazing work Hugo has done through the years.

Leave a Comment

Things to Note for a SQL Server to Postgres Migration

Published 2026-10-26 by Kevin Feasel

Amy Abel has a list:

This week I went back through my PostgreSQL notes and listed what is different between SQL Server and Postgres. These are the things I would pay close attention to when doing a migration.

Most migration issues are not caused by the data. They come from assuming Postgres works the same way as SQL Server.

Click through for the list. Some of these things are fairly straightforward, but others can be a pretty big deal and necessitate significant rewrites of existing code bases.

Leave a Comment

Where the Business Logic Lives in Power BI

Published 2026-10-26 by Kevin Feasel

Teo Lachev answers a question:

A current engagement calls for migrating a rather elaborate financial dashboard from Qlik to Power BI. Just when we think there is light at the end of the tunnel, another business rule is unearthed in Qlik that we need to convert. These rules range from business calculations and dummy rows in dimension tables to allocation overrides.

This brings us to an important question: Where should all this business logic live?

Click through for Teo’s answer to this question.

Leave a Comment

Thoughts on Automatic Index Compaction

Published 2026-10-26 by Kevin Feasel

John Deardurff shares some thoughts:

Anyone who has managed SQL Server for a while probably recognizes the traditional 5% reorganize or 30% rebuild approach. But those Index Fragmentation Thresholds were completely made up. Primarily as they were simple values to baseline that made it easy to automate. But today we need to ask whether fragmentation percentage is really the best measurement for deciding when an index needs maintenance.

As storage has changed, Microsoft guidance around index maintenance has changed. The question should no longer be; How fragmented is my index? A better question is: How efficiently are the pages being used, and how much work is needed to access my data?

Click through for a demo of what automatic index compaction can do in Azure SQL Database. The two important notes I have are as follows. First, as John points out, automatic index compaction does not update statistics, so you’d still need to take care of that. Second, I don’t think there’s ever a good use case for REORGANIZE.

1 Comment

Building a Windows Lab Environment on Linux

Published 2026-10-26 by Kevin Feasel

Lee Markum builds an environment:

First of all, this will be a blog post series. There is simply too much to cover in one blog post and expect people to read it. This blog post is going to be about how I laid the foundation for what I was planning to build.

At the end of the process, I had a fully functional, four machine lab that looks like the below. I used Windows Server 2025 OS Evaluation Edition. I created a Windows Cluster and set up an Availability Group.

Lee points out some of the difficulties along the way, and I agree that it looks pretty frustrating.

Leave a Comment

Microsoft Fabric Tenant Settings and the Govern Tab

Published 2026-10-26 by Kevin Feasel

Heidi Hasting sees something new:

Hiya!

“Ooh, what’s this?”

That was me this week, poking around the OneLake catalog. It keeps getting better and better, and I spotted something that made my admin heart very happy. The Govern tab now has Configurations > Tenant settings, right there in the catalog.

Click through to see what’s there. It’s still not ideal for non-admin users, as Heidi points out, but it is a marginal improvement over what was there before.

Leave a Comment