The cascade-persist subelement applies to all relationships in the persistence unit.
Specifying this subelement adds the cascade persist option to all relationships in addition to any settings
specified in annotations or XML.
The cascade-persist subelement cannot be overridden in this release.
The ability to override the cascade-persist of the persistence-unit-defaults
element will be added in a future release of this specification.
Why can't other types, such as cascade-remove, cascade-refresh,etc. be set globally? Curious and can't figure out the answer.
OK, so that other guy knows Java better than I do, but I bet he can't speak Wuhanese(a Chinese Dialect) like me.