redb: Slow to open large database

We recently restarted ord, and the database was pretty slow to open, on the order of a minute or two. I’m not sure it was the culprit, but I think this was the first time we used a WriteStrategy::Checksum database on mainnet. Under what circumstances will redb check all the checksums for a database using WriteStrategy::Checksum? Is it every time the database opens, or only after a crash?