hesela.devPowersafe overwrite
Powersafe overwrite is the storage property that an interrupted file write leaves bytes outside its requested range unchanged.
This property does not constrain the target bytes to an entirely old or new value and does not establish durable completion. [1] SQLite reports PSOW separately from atomic-write size, safe-append and sequential-write capabilities. [2] A psow URI parameter changes an assumption in supported VFS implementations; it is not a hardware test and may be ignored by a custom VFS. [3]
Relations
- related
- torn-write, rwf-atomic, physical-sector, power-loss-protection, crash-consistency
Limitations
- An unchanged surrounding range can coexist with a torn write inside the target. [1]
Citations
- SQLite: Powersafe Overwrite, scope, assumptions and torn pages.
- SQLite C interface: Device Characteristics.
- SQLite: URI filenames, enabling URI handling and psow overrides.
- Hesela: atomic writes and powersafe overwrite, synthetic byte-state examples.
- Hesela: synthetic recovery-state examples, code hash and executable tests.