Open Session in View: لماذا نُعطّله

في هذا الدرس

understand and disable Open Session in View (OSIV).

الموضوعات المخطط لها

• OSIV keeps the persistence context open until the HTTP response is written.
• It hides LazyInitializationException, but lets queries run in controllers and JSON serialization.
• That means unplanned N+1 and a database connection held for the whole request.
• Spring Boot enables it by default (with a startup warning).
• Set spring.jpa.open-in-view=false and load data explicitly in services.