2009/10/11 Roan:
On Wikipedia, we use one set of DB servers for the wiki database, and a second set for text; this second set is called the external storage. You don't need to worry about this too much, as small wikis typically don't use external storage, but use the text table instead.
The difference view in recent changes is produced by comparing two texts using an external program like diff; it's not stored anywhere (other than possibly in the objectcache table, for caching purposes).
Roan Kattouw (Catrope)
Is there a size range at which it is accepted to be advantageous to move your text out of the standard text table?
Thanks, -Courtney