A dbfile has read-write or read-only status. A dbfile is read-write when it is added, and its runtime read-write status depends on both the read-write status of the dbspace and of the dbfile. The administrator can alter the read-write/read-only status of a dbfile, but cannot alter the online/offline status of a dbfile.
Operations that can be performed on dbfiles include add, drop, rename logical name, and rename the file path. See ALTER DBSPACE statement in Reference: Statements and Options.