Is there another way to excecute batch delettion such as a HSQL like:
delelet pack.AnEntity where pack.AnEntity.aProperty > 0 ?

The method delete(String query) provided by the session implementation seems not to do the deletion effetively. First, it finds all entities according to the query and then deletes them one by one. Secondly, the find(String query) will load all propertis of each entity.

Does anybody have expirence in effitive batch deletion, as well as excecuting a HSQL like update or delete?

Thanks in advance.

Not currently possible. Eventually the bulk update functionality *may* be added.


Of course. It needs to know how to execute cascades.


Yes, this could be optimized.

I always wondered if this is really true. AFAIK, this also happens when there are no cascades defined, and this should be known in advance. I agree that in the case of cascades, every element has to be fetched before it can be deleted, but is it also necessary when there are no cascades defined?

Just an idea, maybe I'm wrong...

Greetings,
Christian

Cascading is just one (major) example of why.

In some of my apps using Hibernate, I have implemented auditing systems using Hibernate Interceptors. Without those entities getting loaded first, those apps would have no way to catch notifications that entities were just deleted.

Or what if the application itself is implementing cascade semantics through Interceptorsand/or Lifecycle callbacks? How could that work if we did not load the entities first and fire the various delete notifications?

You have to keep in mind that Hibernate is an Object Relational Mapping tool. Notice "Object" comes first and that I bolded it. Theres a reason for that. The object model is what is important here.

Now, as I mentioned, I think this can be improved such that the delete does not necessarily need to execute deletes one-by-one in these cases (queries and cascdes). But that does not mean that we should get around the loading of entities to delete them.

That being said, Hibernate 3 completely opens this up with its event-driven architecture. It basically says "OK, here's a request do whatever the hell you want even if we do not think its kosher as a core feature". There you would be free to implement loadless deletes if you so want.

Many thanks to you all.

A question similar to gruberc's: Is it necessary to check the nullability of a property (a primary type) when deleting a transient object with its identitfier?

Cheers

James