Today a doubt about the DB_FILES parameter has emerged, it is clear that includes the datafiles, but the question was whether it included temporary files.
You can see the DB_FILES parameter from the command sqlplus
show parameter DB_FILES
To find the number of current data files you can run the following query;
SELECT COUNT (*) FROM DBA_DATA_FILES;
To find the number of temporary files you can run the following query;
SELECT COUNT (*) FROM DBA_TEMP_FILES;
DB_FILES parameter NOT include the temporary files.
HTH – Antonio NAVARRO.