EF Core 9 Performance: AsNoTracking, Split Queries & Compiled Queries

Why EF Core Performance Matters

ORM overhead is real. These three techniques address the most common bottlenecks in enterprise .NET apps.

1. AsNoTracking

var posts = await db.BlogPosts
    .AsNoTracking()
    .Where(p => p.Status == PostStatus.Published)
    .ToListAsync();

2. Split Queries

var posts = await db.BlogPosts
    .Include(p => p.Tags)
    .Include(p => p.Comments)
    .AsSplitQuery()
    .ToListAsync();

3. Compiled Queries

private static readonly Func<BlogDbContext, string, Task<BlogPost?>> GetBySlug =
    EF.CompileAsyncQuery((BlogDbContext db, string slug) =>
        db.BlogPosts.FirstOrDefault(p => p.Slug == slug));

Conclusion

Profile first with dotnet-trace, then apply these techniques where they matter most.