Testing SQL Server 2025 Resource Governor tempdb Limits with a Query that Spills a Terabyte

SQL Server 2025 introduces a new Resource Governor capability to manage tempdb usage, along with making Resource Governor available in Standard Edition.

I wondered: can Resource Governor’s new tempdb feature help contain queries that don’t use temporary tables, but which spill massive amounts of data to tempdb? The docs say yes, but I always like to get hands-on experience when I can.

I’ve got an awful query that spills like a soft-serve machine choosing violence. Let’s test drive the new tempdb governance features in SQL Server 2025.

Continue reading

Erik Darling and Kendra Little Talk AI, Databases, and SQL Server 2025

Erik Darling joins me on the Dear SQL DBA Podcast to chat about AI tools, why they work better for Python and PowerShell than SQL, and what’s exciting (and what’s not) in SQL Server 2025.

Along the way we describe the ONE THING we always want to configure in Resource Governor, why at least one SQL Server 2025 feature should be backported to 2022, and whether the universe is text files all the way down.

Continue reading

Getting Around Error 40510 to Configure Resource Governor in Azure SQL Managed Instance

One feature I’ve not appreciated enough in the past in SQL Server is Resource Governor.

Resource Governor allows you to fix problems with Memory Grants in a simple way, as Erik Darling recommends. It also lets you classify sessions into groups and limit the maximum number of simultaneous requests, and /or limit the degree of parallelism if you need more CPU for other workloads. While this will slow down the queries you classify into that group, this can be super useful, especially if you’re already using something like Snapshot isolation to prevent blocking or you are using a read-only replica.

In Azure SQL Managed Instance, you get to use Resource Governor, even in the General Purpose tier. This is awesome.

Just make sure you execute commands in the context of the master database, or you’ll get error 40510: Statement 'ALTER RESOURCE GOVERNOR' is not supported in this version of SQL Server.

It is supported! Just USE master; before running your commands.

Continue reading