One of my developer trying to use DynamicQueryEngine.UseNoLockHintOnSelects = true to fixing the query performance. But when I read the manual in this link, https://www.llblgen.com/documentation/5.3/ReferenceManuals/LLBLGenProRTF/html/9363447C.htm , it says that _UseNoLockHintOnSelects _may cause more blocking. How can blocking occurs because as I understand it will work same as READUNCOMIT Isolation level?

WITH NOLOCK is not recommended though in high volume databases with a lot of rows, it can be a lot of blocking can occur because SqlServer forces readers to block writers and vice versa.

Thank you!

That's indeed an error in the docs. We'll correct it for the supported versions. Thanks for the heads up!

What performance issues were you running into btw? The particular feature is a rather old one and is a setting that's applied to all queries. We introduced in v5.1 a per-query target/query hints in v5.5, which might be better suited in your situation.

While looking into why that remark was there in the first place, I ran into: https://bertwagner.com/2017/10/10/how-nolock-will-block-your-queries/

So nolock isn't without locks. It therefore depends on what the query is doing, and when. We'll still remove the wrong remark tho