If you are doing migrating to a new filesystem and moving files, it may be a good idea to check before migrating the filenames are unique across all filesystems by running the following query you find the files that have the same name.

If the query returns no rows found then you don’t have duplicate filenames.

SELECT SUBSTR(file_name, instr(file_name, ‘/’, -1))
FROM (SELECT file_name FROM dba_data_files
UNION ALL
SELECT file_name FROM dba_temp_files
UNION ALL
SELECT member as file_name FROM v$logfile
UNION ALL
SELECT name as file_name FROM v$controlfile)
GROUP BY file_name
HAVING COUNT(1) > 1;

Note: On windows the filenames are not case-sensitive so adding upper/lower to convert to same case would be required to ensure filenames are unique.