Optimized Locking part 2: Lock After Qualification

Optimized Locking part 2: Lock After Qualification

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SQL Server 2025 introduced Optimized Locking. Not one, but two features, sharing a single marketing name.

Lock After Qualification (LAQ)

One of these two features is Lock After Qualification (LAQ). This feature avoids the scenario where a delete or update is blocked by a locked row that would not qualify. But, like any good thing, there is a price. This video shows the feature, explains how it works, and shows some of the potentially undesired side effects.

More of me?

Was this useful to you? Do you want to learn more from me?

You can click here to see an overview of my scheduled conference talks. If you attend one of those, you get a lot of other presenters and sessions thrown in as well!

To learn really everything about SQL Server execution plans, check out my video training. Over 20 hours of super high quality video content (and more will be added when ready).

Or you can hire me to fix the performance problems on your server, or for in house training.

Hugo Kornelis
Hugo Kornelis is an established SQL Server Community expert. He writes, blogs, speaks, tech edits, and researches, focusing mostly on SQL Server performance and execution plans. He was the technical editor for the third edition of Grant Fritchey's "SQL Server Execution Plans". In 2018 he started a project to document all behaviour of SQL Server execution plans at his website, "the SQL Server Execution Plan Reference" (https://sqlserverfast.com/epr) When not working for the community, Hugo is busy at his day job: freelance database developer/consultant. Hugo has over 20 years of experience on SQL Server in various roles. He has a strong database design background but has since specialized into query tuning and execution plans.
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Hugo Kornelis

Married, father of 2 children.

Awarded 18x MVP (2006-2016; 2019-now), in the areas SQL Server and Data Platform.

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