Incomplete ranks shown while CAD is running

[jonatanklosko]

We have the manually-triggered background job for computing ranks information (CAD). For each of the ranks tables, it removes all rows, then computes and inserts fresh rows. While the computation is running, the ranks tables have missing information, which surfaces in the UI and API.

Here are a few screenshots while running CAD on the staging, where it can be seen how CAD progresses:

Screenshots

• Records showing only average as ConciseSingleResults are being computed
• Records showing only single as ConciseAverageResults are being computed
• Incremental entries in the profile as RanksSingle are being computed

The same issue affects API endpoints that rely on ranks (records, WCIF personal bests), and that is a bigger problem, because API users definitely don't expect records to suddenly have no entries.

For more context, I believe this is the underlying issue behind a few strange false-positive record tags we've seen on WCA Live https://github.com/thewca/wca-live/issues/145.

Note that some of the pages/endpoints are cached, so keep that in mind when reproducing.