On Fri, Jan 21, 2011 at 10:43 AM, Roan Kattouw <roan.katt...@gmail.com>wrote:
> 2011/1/21 Platonides <platoni...@gmail.com>: > > If we wanted to map it to a page/revision format, it seems quite > > straightforward. I'm missing something, right? > > > You're missing that migrating a live site (esp. Commons, with 8 > million image rows and ~750k oldimage rows) from the old to the new > schema would be a nightmare, and would probably involve setting stuff > to read-only for a few hours. > If one's clever about it, this could probably actually be done on-the-fly in a reasonably non-evil fashion. Image version data isn't used as widely as revisions; eg things like Special:Contributions always needed direct access to old revs looked up by author, whereas I think image old versions are pretty much only pulled up by title, via the image record. There are also relatively few revisions per file -- old images usually only have a few revisions, and cases of thousands of versions are I suspect very rare -- which would make the actual conversion work relatively lightweight for each file record. Further optimizing by delaying on-demand migration of a record until write time could also keep it from being a sudden database & i/o sink. If indirect lookups won't be needed, we can just keep reading the existing image/oldimage records until they need to be updated on modification (or get updated by a background task at leisure). -- brion _______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l
