Preload: A boolean property. If true, OpenJPA will eagerly load the repository on EntityManagerFactory creation. As a result, all Entity classes will be eagerly loaded by the JVM. Once MetaData preloading completes, all locking is removed from the MetaDataRepository and this will result in a much more scalable repository. If false, the repository will be lazily loaded as Entity classes are loaded by the JVM. The default value is false.