Attaching presentation I made for my colleagues regarding unit testing. Google docs version.
The whole series of NHibernate performance issues isn't about simple use-cases. If you develop small app, such as simple website, you don't need to care about performance. But if you design and develop huge application and once you have decided to use NHibernate you'll solve various sort of issue. For today the use-case is obvious: how to insert many entities into the database as fast as possible? Why I'm taking about previous stuff? The are a lot of articles how the original NHibernate's purpose isn't to support batch operations , like inserts. Once you have decided to NHibernate, you have to solve this issue. Slow insertion The basic way how to insert mapped entity into database is: SessionFactory.GetCurrentSession().Save(object); But what happen when I try to insert many entities? Lets say, I want to persist 1000 libraries each library has 100 books = 100k of books each book has 5 rentals - there are 500k of rentals It's really slow! The inser