[parasubvert]

This is one reason why Oracle is still the gold standard. when entering hot backup mode, which is what you do during a snapshot, it logs the FULL BLOCKS that are changed. Failures and inconsistencies can be replayed from the archive logs.

Of course this means you can quickly blow out your log archival , so it's meant to be a transitory mode:

[saurik]

PostgreSQL has this exact same feature.