RMAN-06094: datafile must be restored // RMAN-06094: datafile 50 must be restored

RMAN-06094: datafile <dbfNo.> must be restored

Error Message:
RMAN> RECOVER DATABASE NOREDO;

Starting recover at 13-JUL-15
using channel ORA_DISK_1
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of recover command at 07/13/2015 05:27:38
RMAN-06094: datafile 50 must be restored


CAUSE:
Backup of datafile <dbf> not available in RMAN catalog.


Solution:
Take fresh backup and restore by below comamnd,
RMAN>RECOVER DATAFILE 15;

Example:
RMAN> restore datafile 50;

Starting restore at 13-JUL-15
using channel ORA_DISK_1

channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00050 to /prod/data/data01/a_txn_data11.dbf
channel ORA_DISK_1: reading from backup piece /prod/backup/standby/Jul_13/FORSTANDB_dbf5028qbu25o_1_1
channel ORA_DISK_1: piece handle=/prod/backup/standby/Jul_13/FORSTANDB_dbf5028qbu25o_1_1 tag=DBF15
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:02:25
Finished restore at 13-JUL-15