I didn't answer your second question because I have no idea what "auto clean a map" means. Maybe you could clarify?
As for what the Mac does to maintain itself, of course I know. It does several things, including automatic deletion of temp files, auto-defragmenting (files under 20MB), auto-optimizing (google "Mac drive hot zone" if you want to know more about that), and runs routine UNIX scripts for daily, weekly and monthly maintenance, which includes such things as log rotation, clearing temp files, garbage collection and cache maintenance.
More detail that I could ever go into here:
Running Mac OS X Maintenance Scripts