Tutorials Entity Framework Core Tutorial
AsNoTracking in EF Core
AsNoTracking in EF Core: free step-by-step lesson with examples, common mistakes, and interview tips — part of Entity Framework Core Tutorial on Toolliyo Academy.
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Entity Framework Core Tutorial · Lesson 55 of 100
AsNoTracking in EF Core
Beginner ✓ → Intermediate ✓ → Advanced → Professional
Advanced · 3 — Production skills · ~10 min · Module 6: Advanced EF Core
What is this?
AsNoTracking tells EF not to snapshot entities in the change tracker — ideal for read-only queries returning DTOs or display data.
Why should you care?
ShopNest homepage reads thousands of products without updates — tracking them wastes memory and CPU.
See it live — copy this example
Paste into a .NET project with EF Core packages, then run with LocalDB/SQL Server (dotnet ef / dotnet run).
var banners = await _context.Products
.AsNoTracking()
.Where(p => p.IsFeatured)
.Select(p => new { p.Id, p.Name, p.Price })
.ToListAsync();What happened?
- AsNoTracking skips change tracker entries.
- Combined with Select projection, EF materializes lightweight results with no update overhead.
Practice next
- Add AsNoTracking to read-only API queries by default.
- Use AsNoTrackingWithIdentityResolution if deduping same entity twice in graph.
- Remove AsNoTracking when you intend to edit loaded entities.
- Set dbContext.ChangeTracker.QueryTrackingBehavior = QueryTrackingBehavior.NoTracking globally.
- Compare Gen2 GC pressure with tracking on vs off in load test.
Remember
AsNoTracking disables change tracking. Default for read-only endpoints. Required for best read performance at scale.
ShopNest browse API
Category listing uses AsNoTracking projection serving 5k RPS read replicas.
Outcome: 40% lower memory per instance vs tracked queries in load test.
Interview prep for this lesson
Practice these questions aloud after reading—each links to a full structured answer.
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