Hibernate: Bulk update bypasses the persistence context

It is fast, but entities already loaded keep their old values until you clear the context.

Code

@Modifying(clearAutomatically = true, flushAutomatically = true)
@Query("update Order o set o.status = :to where o.status = :from")
int bulkTransition(@Param("from") Status from, @Param("to") Status to);

Output

update orders set status=? where status=?   -> 4213 rows in one statement

Without clearAutomatically, an Order already in the session
still reports the OLD status.