SAP Note 26312 - SAPDBA: data file "" could not be created.

Symptom:

The following problem occurs during the restore/recovery with SAPDBA:
After the successful restore of all data files of the database, SAPDBA possibly tries to create further data files with "ALTER DATABASE CREATE DATAFILE ..." and reports:
SAPDBA: The specified datafile does not exist
or the size is not specified.
SAPDBA: The restore of datafiles failed, the database was changed.
SAPDBA: data file "" could not be created.

Cause and prerequisites

SAPDBA selects the files belonging to the database from v$datafile.
As a result, SAPDBA reads an empty file name in a double line due to the ORACLE bug described in note 21762 and tries to generate the file "" instead of ignoring it.

Solution
The ORACLE bug should be corrected as of Version ORACLE 7.3.
SAPDBA will ignore empty file names as of 3.0B or 2.2G (2.1M).

If the error occurs, as described, after the restore, you cannot continue with sapdba. Check the log to determine that no other errors occurred during the restore. This is most likely.
Then you have to recover manually:
sqldba lmode=y
SQLDBA > connect internal
SQLDBA > recover database [until ...]; (see notes 4161, 4164)
SSQLDBA > alter database open [resetlogs];
SQLDBA > exit


To avoid the same error during the next restore/recovery, it would be possible to delete the unnecessary entry from the control file. However, this can only be done by recreating the control file:

complete OFFLINE backup of the database! sqldba lmode=y
SQLDBA > connect internal
SQLDBA > alter database backup controlfile to trace;
You can now edit the file $ORACLE_HOME/saptrace/usertrace/ora_.trc (delete the comments) and use it to recreate the control file: SQLDBA > !cd saptrace/usertrace
SQLDBA > ora_.trc
SQLDBA > exit