Does Hibenate offer a way to update or delete database table rows
without instanciating java class instances?

Hibernate does support such a construct for bulk deletions using the
Session.delete( String query ) method, but this method seems to
send one sql statement per object, what is not really performant.

I think, hibernate should support bulk update and delete via HQL,
because this should be easy to implement, high performant and
also hides the complexity of SQL from the developer (and
perhaps the end user).

txh,
Juergen

No, this is not supported and it is not very easy to implement. When deleting objects, Hibernate has to consider cascades, lifecycle objects and others. Use plain SQL for bulk updates and deletes.

OK, I see the problems (better: lot of work to be done ;-)

What is hibernate currently doing, if another user deletes table rows and I want to sync
this changes into my session's objects?

This seems to me an analog problem, that should already be solved in hibernate...

This is really not a problem. "Syncing" two database transactions (Sessions) would be no transaction isolation. This is what you don't want to do.