Running the `python -m util.backfillreplication` script against a Quay instance with ~6 million images is estimated to take well over 30 days to complete.

A version of the script modified to do nothing but fetch the manifest blobs, ran at a pace that would take those 30 days just to iterate through the 16 million results. Since there are only about half a million layers that are under-replicated, a maximally efficient script could be expected to queue the correct items within 24 hours.

We have a sample query that inverts the logic to avoid the full iteration.