• JPA One-To-One 참조
• Hibernate 5.x Bytecode enahcement with Gradle/Maven
• Some explanations on lazy loading (one-to-one) |JBoss Developer
• @LazyToOne
• Proxies and lazy loading in Hibernate

• NO_PROXY 는 기본적으로 bytecode enhancer를 사용해서 자동으로 구현하는 방식. Bytecode Enhancer 활성화를 해줘야 한다.
• Hibernate Bytecode Enhancement - DZone Java
• Bytecode Enhancement
• java - Hibernate Lazy Loading with @LazyToOne(LazyToOneOption.NO_PROXY) - Stack Overflow class_enhancer(AvailableSettings.USE_CLASS_ENHANCER) 활성화 필요.

<property name="hibernate.ejb.use_class_enhancer" value="true"/>

• https://stackoverflow.com/a/18423704/1051402
• JPA implementation patterns: Lazy loading — Xebia Blog
• Bytecode Instrumentation and Lazy Loading In JPA | Behind Java

• Proxy를 사용하지 않지만 Byte Code Instrument 없이 직접 구현하는 방식.
• Just on JAVA: Lazy one-to-one inverse relationships in Hibernate
• hibernate OneToOne lazy 구현하기
• FieldHandled
• FieldHandler