On Windows systems, mode is ignored.

On UNIX systems or in IEEE/ANSI Std 1003.1 (POSIX) environments, files are created with mode mode (as described in chmod(2)) and modified by the process' umask value at the time of creation (see umask(2)). Created files are owned by the process owner; the group ownership of created files is based on the system and directory defaults, and is not further specified by Berkeley DB. System shared memory segments created by are created with mode mode, unmodified by the process' umask value. If mode is 0, DB XML will use a default mode of readable and writable by both owner and group.