Tag: CQRS

All the articles with the tag "CQRS".

• [JPA + Spring Mastery 09] When to use what — a JPA / JPQL / Native SQL decision tree, cuts drawn by four measurements

  8 May, 2026

  Across eight prior posts, this series unpacked PersistenceContext / Dirty Checking / Optimistic Lock / N+1 / IDENTITY / self-invocation / Saga·Outbox with measurements. This finale lays that evidence on a single decision tree — starting with the first fork (domain unit vs data unit), then five places where JPA Dirty Checking shines and five where it bleeds, JPQL's middle ground, and the seat for Native / JdbcTemplate / MyBatis. Four measurement cuts (Dirty Checking 132× / saveAll IDENTITY ~1000× / OFFSET 1M 570× / bulk JPQL vs Dirty Checking 84×) decide the boundaries, anchored on Eric Evans' Aggregate (DDD 2003), Fowler's Identity Map / Unit of Work (PoEAA 2002), Greg Young's CQRS Documents (2010), and Vlad Mihalcea's **High-Performance Java Persistence** (2016). The entry point you can hand over in a single URL when an interviewer asks 'how have you used JPA?'