Comparison
Right to erasurevsSnapshot expiry
Right to erasure
a person asks to be deleted and you have to find them in the warehouse, the lake, every backup and last quarter's exports.
A person's legal right to have their personal data removed, which a data platform must be able to honour within a deadline. It is architecturally awkward because analytical storage is built to be append-only and immutable, so the answer is usually a combination of pseudonymisation, key deletion and targeted rewrites. Snapshot retention and time travel are the parts most often forgotten, since a deleted row remains readable in an old snapshot until it expires.
Full entry →Snapshot expiry
you deleted the rows a month ago and the bytes were still in the bucket, because the old snapshots still referenced them.
The maintenance operation that drops old table versions and physically removes the files only they referenced. Until it runs, deleted data is still on disk and still costs money, and it is still readable by anyone who can query an old snapshot. That makes it a privacy control as much as a cost control, and it is the step most often missing when a team implements erasure requests against a lakehouse.
Full entry →