With a little delay I found people complaining about the schema file missing from the db2hbm deployed package. Now the file is included in the download package, and yanch provided a shortcut in the doc to download the file from sourceforge. Thanks!

Well, a few word about db2hbm and Oracle ( and any other database but MSSQL now ). I used the schema information provided by NH as long as possible, but these information does not provides the required details in order to discover completely the foreign keys, and foreign keys are necessary for creating associations. Not really an NH problem, actually NH leverages ADO.NET for schema inquiry, but ADO.NET seems to miss the foreign key part. So the only solution to have db2hbm working for all database is to provide a custom foreign key crawler for the DB.