> This is a follow-up post to my PSA: SQLite does not do checksums and PSA: Most databases do not do checksums by default.

That's really all there is to it.

SQLite has very deliberate and well-documented assumptions (see for example [1], [2]) about the lower layers it supports. One of them is that data corruption is handled by these lower layers, except if stated otherwise.

Not relying on this assumption would require introducing checksums (or redundancy/using an ECC, really) on both the WAL/rollback journal and on the main database file. This would make SQLite significantly more complex.

I believe TFA is mistaken about how SQLite uses checksums. They primarily serve as a way to avoid some extra write barriers/fsync operations, and maybe to catch incomplete out-of-order writes, but never to detect actual data corruption: https://news.ycombinator.com/item?id=44671373

[1] https://www.sqlite.org/psow.html

[2] https://www.sqlite.org/howtocorrupt.html