As Oracle 11.1 you can use file from a standby(physical) database and move them to the primary.
We went thru to the Standby and determined which datafiles were in the particular group and then connected to primary from the standby as an auxiliary and copied the files over the network to the different diskgroup.
connect sys@standby AUXILIARY sys@primary; BACKUP AS COPY DATAFILE 2 AUXILIARY FORMAT '+DATA/COPY_FILE/COPY_FILE.dbf; .. ..Once the Files are copied you can switch the datafiles .
CATALOG DATAFILE COPY '+DATA/COPY_FILE/COPY_FILE.dbf'; RUN { SET NEWNAME FOR DATAFILE 2 TO ''+DATA/COPY_FILE/COPY_FILE.dbf'; SWITCH DATAFILE 2; }This will allow for a move of the datafile as well as rename on the primary.
you will then have do a crash recovery on the datafile(s) in question.
recover database 2; alter database datafile 2 online;you have just copied a file over the network and plugged it into your primary from standby. This is a pretty convenient if accidents happens.