Q. external database updates

hi all I am trying to set up the following scenario: db 1 on instance a db 2 on instance b ( may be on the same or a different host ) I would like table x on db 2 to have a foreign key constraint referencing table y on db 1, is this possible? I would also like a query which runs on db 1 to also update a table on db 2. again, is this possible? I have managed to create a synonym on db 2 pointing to table y on db 1, but I get this error when trying to create the constraint: -556 Cannot create, drop, or modify an object on an another database server. is there a way round this ? informix version is 7.20.UC3 OS is HPUX 10.20 any suggestions much appreciated TIA Pete