EF Core performance techniques at a glance

Technique	Description	When to use, and the benefit	Key snippet
DbContext pooling	Reuses DbContext instances to reduce initialization overhead.	High-throughput applications, for example ASP.NET Core, that create many DbContext instances. Reduces allocation and setup cost.	services.AddDbContextPool<MyContext>(...)
Compiled queries	Pre-compiles LINQ queries into .NET delegates, bypassing runtime compilation and cache lookup.	For very frequently executed (“hot path”) queries where profiling shows the compilation overhead is significant.	EF.CompileAsyncQuery((MyContext ctx, int id) => ctx.Entities.Where(e => e.Id == id))
AsNoTracking()	Disables change tracking for queried entities.	Read-only scenarios where entities won’t be updated. Reduces memory and processing overhead.	context.Entities.AsNoTracking().ToListAsync()
Eager loading	Loads related data as part of the initial query, using Include() and ThenInclude().	When related data is always needed, to avoid N+1 queries.	context.Blogs.Include(b => b.Posts).ToList()
Query splitting	Generates separate SQL queries for included collections, to avoid cartesian explosion.	Queries that load multiple related collections, where a single query becomes inefficient.	context.Blogs.Include(b => b.Posts).AsSplitQuery().ToList()
Global query filters	Defines LINQ predicates that are applied automatically to all queries for an entity type.	Implementing soft deletes, multi-tenancy, or other consistent filtering rules.	modelBuilder.Entity<Post>().HasQueryFilter(p => !p.IsDeleted);
Select projections	Retrieves only the specific columns or properties needed, not entire entities.	When only a subset of the entity data is required. Reduces data transfer and materialization cost.	context.Entities.Select(e => new { e.Id, e.Name }).ToList()

Each one is explained in the query habits noteEF Core query habitsSix habits that keep EF Core queries fast.Opens in a new tab, the pooling and compiled queries notePooling, compiled queries and compiled modelsFour ways to cut overhead in EF Core, and two common mix-ups between them.Opens in a new tab and the loading noteLoading related dataEager, explicit and lazy loading, and the N+1 problem that lazy loading can cause.Opens in a new tab.