thanks for your comments.
i have noted before with some DBs that no matter your access, even though it lists available databases/schemas/catalogs, the driver won't return anything inside unless you have a direct connection to them (as in the 'default').
i imagine if you create 'direct connections to those other DBs it would be fine - i do note thats not actually what you're asking though.
the db/catalog/schema name is passed in as you make a selection and i just tested this on a sample for mysql whose driver does allow you to traverse other DBs and catalogs etc.
i have not connected to netezza before - i'm not really familiar with it. i'll have a read and get back to you again.
thanks again :)