Thanks, but we're not using fluent. Peter
On Monday, March 17, 2014 6:25:35 AM UTC-4, Carel Blumenstock wrote: > > We are using fluent mappings, in order to have changes to child lists not > trigger a version update of the parent we had to state as such in mapping > like Not.OptimisticLock(), hth > > Op maandag 10 maart 2014 20:12:27 UTC+1 schreef Peter V: >> >> We're using NHibernate where the DB can be updated by either a user (via >> GUI) or external systems (via background message handlers). Our DB schema, >> by the way, uses a lot of joins. >> >> So what can happen is, we can get multiple background messages that >> provide exactly the same information, and so trigger repeated writes to the >> DB across all the joined tables that don't actually change anything (other >> than the version). >> >> What I'm trying to figure out is, for performance reasons, is there a way >> to prevent NH from updating the DB if a value hasn't changed? >> >> So when an object's setter is called, NH should first read the current >> value from the DB, and if the new value is the same, do nothing; >> if different or not found, then save/update it. >> >> Thanks, >> Peter >> >> P.S. I was looking through other postings that talked >> about Session.Merge(): >> - >> https://groups.google.com/forum/#!searchin/nhusers/saveorupdate$20merge/nhusers/6_8uwwl5KX4/11Pef_FreXgJ >> - >> http://stackoverflow.com/questions/4725785/stop-hibernate-from-updating-collections-when-they-have-not-changed >> >> ...and I thought Merge() would do what I needed. >> >> But reading some more, I see that Merge is really more about whether the >> instance is already associated with the current session. (Merge will... >> "Copy the state of the given object onto the persistent object with the >> same identifier. If there is no persistent instance currently associated >> with the session, it will be loaded.") >> >> So I'm confused - will Merge() do what I need? Or am I looking in the >> wrong place? >> > -- You received this message because you are subscribed to the Google Groups "nhusers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/nhusers. For more options, visit https://groups.google.com/d/optout.
