Last modified: 2008-08-09 21:34:07 UTC
On enwikinews, I went through a few of our most popular templates, and sighted the latest versions (which predated flaggedrevs being turned on), yet it still added approximately the number of transclusions to the job queue (I'm assuming here it's purging for when it doesnt use the latest version, but the sighted version, of templates to anons). This is unnecessary, as they are already transcluded with the right versions as they predate flaggedrevs, and there are no other sighted versions anyway. This causes quite a bit of work on the job queue, which isn't a big problem for enwikinews where top template is 13K transclusions, but might be for bigger wikis where you get multi-million transcluded templates. Maybe a check for whether the edit being sighted is earlier than the first sighting entry in the log, or something similair that will represent when flagedrevs was installed. (or you could check if there are no other revisions of that page that are sighted, which would do the same thing I presume, and be more useful in the long run)
Whether the template's latest version was made before then doesn't really matter; pages could still use it. Also, checking those dates is pretty hacky.
If it doesnt have any sighted revisions why do you need to purge on both edit and sight?
The templates used on pages depend on the stable versions of templates, so as they change, so should pages that use them.