C# LINQ Performance Fix #1 - Group By Correction 

Thanks :)

I agree with you here. However, some projects provide faster LINQ implementations, and that's something worth considering. There's also context-aware and type-aware LINQ that will do much better than the default implementation and will remain the same level of expressiveness. For example this is a very nice project that provides faster and more type aware LINQ: github.com/NetFabric/NetFabric.Hyperlinq Context-Specific LINQ is a bit harder to generalize but that's kind of the point. Where composition is being done all of the type information and business context gets baked in with the query and the executor will take all of this information and optimize the query. Lastly there's a concept of cost-free / zero-cost abstractions and that's something that has to be implemented inside the compiler but it's doable, just look at Rust as a reference/inspiration point.

@dan That's true but I once was assigned to a project that was taking 2 hours to run a bunch of LINQ queries on a large dataset. The data analysts could only perform one or two runs per day. Just by making some changes to the queries, I reduced it to 20 minutes. By removing LINQ, it could run in less than a minute. I like LINQ but it's important for people to be aware that LINQ can bite you hard.

​@ Yes, that's what I also said too.

Thanks, I need to pay more attention to the code and triple check it next time. Obviously mistakes can always happen but I'm trying to minimize them. New video about LINQ + Structs should be finished in a couple of days :)

Here you go :) #2 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-atUpAx_0lqg.html #3 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-wUY-UdkI6GQ.html