Folgendes sollte funktionieren,
var testObjects = CreateTestObjects(500000);
var stopwatch = new Stopwatch();
stopwatch.Start();
using (IStatelessSession session = sessionFactory.OpenStatelessSession())
using (ITransaction transaction = session.BeginTransaction())
{
foreach (var testObject in testObjects)
session.Insert(testObject);
transaction.Commit();
}
stopwatch.Stop();
var time = stopwatch.Elapsed;
Siehe:http://nhibernate.info/blog/2008/10/30/bulk-data-operations-with-nhibernate-s-stateless-sessions.html