The first run scanned the 58M-row pending table on the HDD once per
6-hour window and starved the prober and the batch store. Now one scan
classes the finished rows and seeds the record, and the waiting rows go
by windows of created_at through their index. The prober's start puts a
previous run's claims back with a status scan of the same table, 20+
minutes after every deploy: a partial index on the taken rows (migration
6900) makes it instant.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
