onload question

When using the onload -d dbspace option, when the original database was unloaded from two dbspaces, does the -d option overwrite both the original dbspaces and write them both to the specified dbspace? If so, is there a way to say, if the database came from dbspace 1, write it to dbspace 3. If it came from dbspace 2, write it to dbspace 4 during the onload? Larry