C# - Performance Issues with Entity Framework Core and Large Data Set Paging
I'm converting an old project and I'm optimizing some code but I'm currently facing significant performance issues when trying to paginate over a large dataset in an ASP.NET Core application that uses Entity Framework Core 6. The dataset contains over a million records, and when I attempt to fetch results using the `Skip()` and `Take()` methods for pagination, the response time is noticeably sluggish, often taking several seconds to load the first page. I have implemented the following query: ```csharp var pageSize = 10; var pageNumber = 1; // This would come from a request parameter var results = await _context.MyEntities .OrderBy(x => x.Id) .Skip((pageNumber - 1) * pageSize) .Take(pageSize) .ToListAsync(); ``` While this retrieves the correct amount of data, the execution time seems excessive. I have also indexed the `Id` column in the database, but it doesn't appear to make a noticeable difference. I’ve tried optimizing the database by examining execution plans and adding additional indexes, but I'm still seeing poor performance. Additionally, I've looked into using `AsNoTracking()` for read-only queries but didn't notice any improvements. When I run SQL directly on the database, the query executes in under a second, so it seems to be an issue with how Entity Framework is processing the request. I also checked the EF Core logging and noticed that it’s generating the SQL correctly, but the execution time is still slow. What could I be missing or what best practices can I adopt to improve the performance for paging large datasets in EF Core? Has anyone else encountered this? I'm working in a Linux environment. What am I doing wrong?