2009/4/7 K. Peachey <p858snake(a)yahoo.com.au>au>:
Currently
undos, so frequent on wikis, just blindly create a duplicate row
instead of checking if the old one could be reused,
https://bugzilla.wikimedia.org/show_bug.cgi?id=18333 . Maybe some hardware
savings could even be achieved.
From my understanding they have to be kept within the system to keep
us within the GFDL licenseing terms.
The text doesn't need to be stored twice, though, just a note that it
is the same text. However, I believe the Wikipedia databases have the
text compressed, so that is effectively what happens already.