Re: [seam-dev] To cascade or not...

On Wed, Mar 4, 2009 at 2:59 PM, Emmanuel Bernard <emmanuel(a)hibernate.org <mailto:emmanuel@hibernate.org>> wrote: class Address { @ManyToOne Country country; @ManyToOne State state; @ManyToMany Set<Person> inhabitants; } It generally makes no sense to cascade persist for these three associations. Even if your app has 80 entities, it's very likely that half of the associations should not be cascaded :) Let's take your proposal PERSIST, DELETE, REFRESH I REFRESH address and changes on Person are lost, doh! True. I was on the fence about REFRESH. I think you convinced me. PERSIST, do I really save an address and expect the person living there to be added to the system. Surely not, the person is very likely to have been built beforehand. Same for Country and State. Not a problem if County and State are managed, which is likely how you attach them anyway. It will even work if they are a non-managed entity with a valid ID. If neither of those are the case, then yes, I want the persist to add them to the database. That's the whole point of the cascade. MERGE Do I really want to update a country when an address changes? I can't find a system that would do that. I don't do MERGE, so I don't care. Cascade has performance consequences. The more cascades the slower your app will be at flush time. Especially on applications with a lot of entities. NONE is a good default, that's why it's the default we have chosen :) I'm still don't agree. I like PERSIST and DELETE. DELETE can be dangerous, but it's also extremely convenient. -Dan -- Dan Allen Senior Software Engineer, Red Hat | Author of Seam in Action http://mojavelinux.com http://mojavelinux.com/seaminaction NOTE: While I make a strong effort to keep up with my email on a daily basis, personal or other work matters can sometimes keep me away from my email. If you contact me, but don't hear back for more than a week, it is very likely that I am excessively backlogged or the message was caught in the spam filters. Please don't hesitate to resend a message if you feel that it did not reach my attention. ------------------------------------------------------------------------ _______________________________________________ seam-dev mailing list seam-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/seam-dev