LINQ query performance optimization when joining large datasets with complex conditions in C#
I'm refactoring my project and I've searched everywhere and can't find a clear answer... I'm working on a project and hit a roadblock. I'm experiencing performance optimization when executing a LINQ query that involves joining two large datasets with complex conditions. I'm using Entity Framework Core 6.0 and have two entities: `Orders` and `Customers`. The `Orders` table can have millions of records, and I'm trying to filter it based on certain criteria from the `Customers` table. Here's the LINQ query I wrote: ```csharp var query = from order in context.Orders join customer in context.Customers on order.CustomerId equals customer.Id where customer.IsActive && order.OrderDate > DateTime.UtcNow.AddDays(-30) select new { order.OrderId, customer.Name, order.TotalAmount }; ``` The scenario arises when I execute the query, as it takes a noticeably long time to process. I've tried optimizing it by adding indexes on the `CustomerId` and `OrderDate` columns, but the performance is still subpar. Additionally, I’ve checked the generated SQL query using `ToQueryString()` and it seems to be using a highly nested structure. I also considered breaking down the query into smaller parts, but that felt like a workaround rather than a solution. Has anyone experienced similar performance optimization with LINQ queries involving joins and complex conditions? What strategies can I use to improve the execution time of this query? Any insights on best practices with LINQ and Entity Framework Core would be much appreciated! The stack includes C# and several other technologies. Any advice would be much appreciated. The stack includes C# and several other technologies. Any pointers in the right direction?