Lazy Load - Issie with Entity Framework Core 8

This project is related to the issue 32708 from Entity Framework Core.

Context

Here we have 2 projects:

• .NET Framework 4.6.1 with EF6
• .NET 8 with EF Core Both of them uses AutoMapper 9.0.0 to map entities from the database to View Models and both of them EF uses Proxies to Lazy Load the entities.

For some unknown reason, the latest version (.NET8 + EF Core) is taking exponentially more time to do this map. And it's important to note that is exponentially, it means that in this given project, with few entities and navigations, the difference may be not much relevant, but in production databases, it leads to unpracticable performance issues. In the issue mentioned, it took from 13 seconds to almost 800 seconds.

How To Run

• Clone the repository;
• Open the SQL Server Management Studio and run the "backup_schema_and_data" to get the data and the schema of the database;
• Change the connection strings in the DataContext files to points to your database;
• Open the "Program.cs" files and put a breakpoint in the lines with "Mapper.Map[...]";
• Run one project and then another to spot the difference;