last month i just create a_txn_data07.dbf since i noticed it i deleted it after that i created a_txn_data06.dbf
but when i start our database i got error something no such file so what i did is to alter database datafile 44 OFFLINE DROP;
then it works our database is now STARTED.
in symantec backupexec i got this error
Starting backup at 04-JAN-13
RMAN-06169: could not read file header for datafile 44 error reason 4
released channel: ch0
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-03002: failure of backup plus archivelog command at 01/04/2013 11:32:40
RMAN-06056: could not access datafile 44
that is why our RMAN terminated when scheduled run in BackupExec.
By using OFFLINE DROP you just have disabled the datafile for further use. The information of datafile is still in controlfile. You need to remove that datafile or else your rman backup willl fail again and again to do so you can follow the following link