2 databases, 1 transaction?

Hi all!

My question is simple may be- Can I do the following:

$this->db->trans_start()
add(edit, delete) a record in database#1,
load database#2,
change $active_group,
add(edit, delete) a record in database#2,
close connection to #2,
change $active_group back,
and, at last, finish with $this->db->trans_complete()
?

Is the $this->db->trans_status() result reliable in this case or not?

Thank you