NHibernate 2.1 updates schema metadata without being asked to

In NHibernate 2.1, the session factory is set up to access the database immediately when you build it. This is done by a Hbm2ddl component to update something called SchemaMetaData: I’m not sure what this is all about, but I am certain that such behaviour is not nice. The previous version of NHibernate didn’t do it, so I expect the new one to behave likewise unless I explicitly order the change.

The solution for this is to add a line to your hibernate.cfg.xml file that says:

<property name="hbm2ddl.keywords">none</property>

Note that completely omitting this setting will actually enable the feature… Did I already mention I don’t like it? I don’t, so much that I decided not to change config files but to hardcode it disabled. I use one global method to load the NHibernate configuration, so this is easy. The code looks something like this:

_configuration = new global::NHibernate.Cfg.Configuration();
_configuration.Configure();
_configuration.SetProperty("hbm2ddl.keywords", "none");