Citation of versions by timestamp? - Wikitech-l

24 Feb 2003

A wikipedian has recently been trying to find a good way to cite
particular revisions of articles in the bibliography for a paper.

Current we can give URLs for the _current_ version of an article
(current as of whenever it is visited), or of _previous_ versions (as of
when the citation was made):

current:
  http://www.wikipedia.org/wiki/Foobar
old:
  http://www.wikipedia.org/w/wiki.phtml?title=Foobar&oldid=12345

There are two main problems with this (aside from the ugliness of the
old-reference URLs):

* There is no way to reference the current version _as of the time of
citation_. Since that revision isn't in the old table, it has no oldid
assigned yet.

* oldid values sometimes can change, as when an article is deleted and
subsequently restored (done also when recombining histories of articles
that have been broken by crude renaming). Possible rearrangements of the
database (such as combining all languages into a single table) could
require reassigning oldids en masse. They are *not* reliable long-term
citations.

One possible solution would be to provide a way of citing articles as of
a particular timestamp, for instance:

  http://www.wikipedia.org/wiki/Foobar?version=20030224161134

which would pull up either a cur or old version with that timestamp.
(It could also be prettified: version=2003-02-24-16:11:34 etc)

Advantages:
* consistent, no fuss, no worries about rearrangement of db structure
* citation URL can be provided in a nice handy link at the bottom of
every page

Disadvantages:
* timestamp has 1-second resolution. Generally this is going to be
unique (at least per article), but it may occasionally not be,
particularly in cases of recombined histories. Some articles had
multiple revisions'  timestamps set to the same time due to bugs in the
rename code and other db tweaks in early '02.
* for this reason it's not suitable as the mainline url for drawing up
old history revisions via the history list; so people have to remember
to find and use the citation url separately

Alternatively, we could supply _both_ timestamp and oldid in the URL,
and let timestamp have priority if an exact match on both is not found.

Thoughts?

-- brion vibber (brion @ pobox.com)