Fontconfig - May 2006 - fontconfig performance

I apologize if I''m being naive, but is it really necessary for
fontconfig
to open 172 files to resolve "serif" ?

    $ strace fc-match serif 2>&1 | grep open | grep fontconfig | wc -l
    172

Perhaps once after a font change, but every time?  Couldn''t the result
of recent lookups be cached?

    $ strace fc-match serif 2>&1 | grep open | grep fontconfig | wc -l
    172

And why are some of those files opened multiple times?
 
    strace fc-match serif 2>&1 | grep open | grep fontconfig | sort -u | 
wc -l
    64



John