Annotation Type Immutable
Mark an Entity, a Collection, or an Attribute type as immutable. No annotation means the element is mutable.
An immutable entity may not be updated by the application. Updates to an immutable entity will be ignored, but no exception is thrown. @Immutable must be used on root entities only.
@Immutable placed on a collection makes the collection immutable, meaning additions and deletions to and from the collection are not allowed. A HibernateException is thrown in this case.
An immutable attribute type will not be copied in the currently running Persistence Context in order to detect if the underlying value is dirty. As a result loading the entity will require less memory and checking changes will be much faster.