Neil, thank you so much for your insightful comments!
I was able to use Quarry to get the number of edits on English
Wikipedia yesterday, so I can indeed get recent data from it—hooray!!!
I also used it to cross-check against the REST API for February 28th:
https://quarry.wmflabs.org/query/25783
and I see that Quarry reports 168668 while the REST API reports 169754
edits for the same period (less than 1% error). I'll do some digging
to see if the difference is from the denormalization you mentioned, or
other reasons why they disagree.
Maybe one more question:
the data requires some complex reconstruction and
denormalization that takes
several days to a week. This mostly affects the historical data, but the
reconstruction currently has to be done for all history at once because
historical data sometimes changes long after the fact in the MediaWiki
databases. So the entire dataset is regenerated every month, which would be
impossible to do daily.
A Wikipedian (hi Yurik!) guessed that this full scan over the data is
needed because Wikipedia admins have the authority to make changes to
the history of an article (e.g., if a rogue editor posted copyrighted
information that shouldn't ever be visible in the changelog). If
articles' changelogs were append-only, then the operation could pick
up where it left off, rather than starting from scratch, but this
isn't the case, so a full scan is needed. Is this a good
understanding?
Again, many thanks!
Ahmed
PS. In case of an overabundance of curiosity, my little project is at
https://github.com/fasiha/wikiatrisk :)