dotnet-linq-optimization
dotnet-linq-optimization
LINQ performance patterns for .NET applications. Covers the critical distinction between IQueryable<T> server-side evaluation and IEnumerable<T> client-side materialization, compiled queries for EF Core hot paths, deferred execution pitfalls, LINQ-to-Objects allocation patterns and when to drop to manual loops, and Span-based alternatives for zero-allocation processing.
Out of scope: EF Core DbContext lifecycle, migrations, interceptors, and connection resiliency -- see [skill:dotnet-efcore-patterns]. Strategic data architecture (repository patterns, read/write split, N+1 governance) -- see [skill:dotnet-efcore-architecture]. Span and Memory fundamentals -- see [skill:dotnet-performance-patterns]. Microbenchmarking setup -- see [skill:dotnet-benchmarkdotnet].
Cross-references: [skill:dotnet-efcore-patterns] for compiled queries in EF Core context and DbContext usage, [skill:dotnet-performance-patterns] for Span/Memory foundations and ArrayPool patterns, [skill:dotnet-benchmarkdotnet] for measuring LINQ optimization impact.
IQueryable vs IEnumerable Materialization
The most impactful LINQ performance decision is where evaluation happens: on the database server (IQueryable<T>) or in application memory (IEnumerable<T>).
The Problem
// DANGEROUS: Materializes entire table into memory, then filters in C#
IEnumerable<Order> orders = dbContext.Orders;
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