2011/4/9 Platonides <Platonides(a)gmail.com>om>:
Yes. Calling a template twice will only fetch the text
once, won't
increase the 'used templates' counter...
Preprocessing of wikitext over a threshold is cached serialized (it's
easier to reprocess if it's too small).
To clarify: there's an in-process cache, like Brion said, so a
template that is used twice on the same page is only fetched and
preprocessed once. However, this only applies to templates called with
no parameters. If the template is passed parameters, this in-process
cache won't be used, even if the same set of parameters is used twice.
What we store in memcached is a serialized version of the preprocessor
XML tree, keyed on the MD5 hash of the wikitext input, unless it's too
small, like Platonides said. This means that if the exact same input
is fed to the preprocessor twice, it will do part of the work only one
and cache the intermediate result.
Roan Kattouw (Catrope)