Hi, just wanted to add that I contacted jtOpen/400's forum (the developers behind the free implementation of IBM's Toolbox / JDBC driver) about this issue, and it looks like that the missing method will be implemented as soon as the server side on the iSeries will support it.
If anyone is interested, the URL is
http://jt400.sourceforge.net
So, for the time being, the only way not to break compatibility with Hibernate is to force getGeneratedKeys() disabled even if the driver reports it is supported and to specify "naming=sql" in the url for jdbc.
Besides allowing Hibernate to use its standard syntax for queries (with the '.'), it is just the Good Choice to use "naming=sql" when using JDBC on iSeries. If you want to call RPG or custom iSeries commands you can always use a separate connection from the Toolbox.
Regards,
Giulio