I want to switch read-write transaction and read-only transaction with google-cloud-spanner-hibernate.
In JPA, LockMode is set for each Query, but not for each Transaction. Is there any way to control it in google-cloud-spanner-hibernate?
I found a solution from the Hibernate forums which may help. If you're using native Hibernate, you can do something like this:
Session session = sessionFactory.openSession();
((SessionImplementor)session).connection().setReadOnly(true);
session.setHibernateFlushMode(FlushMode.MANUAL);
session.beginTransaction();
... do your work ...
session.commitTransaction();
This will make the underlying connection use a read-only Spanner database transaction. The casting operation seems a little unusual... I'll followup and ask the Hibernate folks on what they recommend exactly but this can at least be a workaround. You can see similar casting operations done in the Spring HibernateTransactionManager, so maybe it is common practice.
If you are using Spring, you will have access to a more elegant method - the @Transactional(readonly = true) annotation. More info here.