What problem does it solve? EF Core queries often suffer from N+1 command patterns, over-fetching, unnecessary change tracking, and cartesian explosion, causing high database load and slow response times. This Skill provides a measurement-first workflow to identify and fix these query-shape problems without breaking tenant isolation, authorization, or repository boundaries. ## Core Features & Use Cases - Query Diagnostics: Capture EF command logs, generated SQL, durations, and row counts to pinpoint N+1, over-fetch, tracking, and premature materialization issues. - Query-Shape Fixes: Apply targeted rewrites such as moving filters before materialization, replacing Count with Any, projecting only required values, adding AsNoTracking, and using AsSplitQuery for proven collection-join explosion. - PostgreSQL Verification: Inspect translations with ToQueryString, validate hot paths with EXPLAIN (ANALYZE, BUFFERS), and confirm index use and round trips on the production provider. - Use Case: A repository method loads events with their sessions and tags, generating dozens of SQL commands per request. Use this Skill to capture the command logs, apply projection and split queries, and verify the query count drops while tenant isolation tests still pass. ## Quick Start Analyze the slow event list endpoint for N+1 queries and rewrite the repository query to use projection and AsNoTracking, then verify with the integration tests.
