That can mean as much as "you have to encrypt everything with a separate key, so that you can destroy the key for the given (say, personally identifiable) dataset making its retrieval irrecoverable"
I'm not saying that's the particular compliance reason they had here, or that the analysis you're giving is wrong, either. There is an interpretation where either of these ideas could be the correct one.
If this weren’t a concern, regulations would demand immediate deletion of data.
there's a whole lot of people in here who are way too quick to assume that just because one part of a permanent deletion process was inadvertently triggered and then caught while they still had backups, their whole permanent deletion process is a lie.
You seem to be right-ish, while the gdpr in certain circumstances allows you to keep backups of data that should have been deleted it seems like they are trying to discourage it in the future.
> ...It is, however, important to note that where data put beyond use is still held it might need to be provided in response to a court order. Therefore data controllers should work towards technical solutions to prevent deletion problems recurring in the future.
Also, modifying backups is a great way to inadvertently hose your backups.
It's your job to use technics which allow you to do this like using encryption on your backup and deleting the keys for it, for example.
Exactly. I'm not aware of any laws saying "you must delete this data immediately". More like "within X days or months". The permanently delete thing presumably skips some cooling-off period in the online database but not the backup, which seems perfectly appropriate, provided your backup retention is compliant.
Google has a nice page describing out their deletion process. [1] It doesn't go into product-specific technical details/steps (like marked as deleted within the product, row deleted from Bigtable/Spanner, major compaction guaranteed to happen, backups guaranteed to be deleted or unusable) but it says this:
Google> We then begin a process designed to safely and completely delete the data from our storage systems. Safe deletion is important to protect our users and customers from accidental data loss. Complete deletion of data from our servers is equally important for users’ peace of mind. This process generally takes around 2 months from the time of deletion. This often includes up to a month-long recovery period in case the data was removed unintentionally.
This is a best practice.
Delitio> It's your job to use technics which allow you to do this like using encryption on your backup and deleting the keys for it, for example.
If they'd thrown away the encryption key immediately, this would have been much worse. Instead of "we're down for 2 weeks?!?" (already quite bad) it'd be "our data is gone forever?!?". You never want to delete anything too quickly for exactly this reason.
[1] https://policies.google.com/technologies/retention?hl=en-US
Going back and purging things from the backups as part of the delete process would be overdoing it to a ridiculous degree.