DB_FILES initialization parameter determines the maximum number of datafiles. A change in this parameter requires a restart of the database.
The default value of DB_FILES is operating system specific.
When determining a value for DB_FILES, you should consider the following situations:
i. If the value of DB_FILES is too low, you cannot add datafiles beyond the DB_FILES limit without first shutting down the database.
ii. If the value of DB_FILES is too high, memory is unnecessarily consumed.