Wow!!! NHibernate second level cache rocks!. Before enabling the NHibernate second level cache in my Castle web application, a controller accesing several models in the database delayed about 40 seconds in process and render a request. This becomes the application useless but is comprehensible, is the cost of relational objects because Im accesing the database several times with my objects and their relations. Thanks to the second level cache and the easy method to enable it in my ActiveRecord models, now the same request is processed in 1 second. Yes! 1 second!!!. I want to say thanks to ActiveRecord and NHibernate hackers (in special to Kevin Williams and Ayende Rahien for the help) for their efforts and really impressive work.
Read this to learn how to enable the cache in ActiveRecord.