* Aryeh Gregor <Simetrical+wikilist(a)gmail.com> [Sat, 16 Jan 2010
23:06:06 -0500]:
You can do this with database queries fine -- there
are already
several different toolserver tools that will do category intersections
for you, and a couple extensions. In fact, bog-standard search will
do it for you, although AFAIK only for categories added literally (not
by templates):
http://en.wikipedia.org/w/index.php?title=Special:Search&redirs=1&s…
Intersections probably are inefficient when
someone needs a range search
between, let's say 1944 and 1965. SMW has probably right approach that
something sequental and numerical like date, mass, speed should not be a
Category but a Property..
Also, it's a bit sad that so many toolserver tools are standalone and
are not a part of MediaWiki distribution. That tool should be a part of
Special:Search.
> It wouldn't be that hard to allow template-added categories too. I
> assume you have categories like "books published in America", "books
> published in 1872", and "biographies" -- if not, you can easily add
> them via your templates (although that wouldn't work right now with
> standard search AFAIK, it would work with things like CatScan).
When comes to subcategories, I always wondered
why they have to include
the name of parent category:
http://en.wikipedia.org/wiki/Category:Books
The word "Books" is repeated many times through the nested categories,
although we already know these are the "Books".
However, this brings the problem with "de-parenting" of categories,
which is hard to resolve, because the Categories are the part of source
text.
Perhaps, a full category name and a shorted subcategory alias, defined
at NS_CATEGORY pages.
Dmitriy