I am developing a new system and I ponder using Eventstore (once again) as the storage back-end.
My main concern is that I wont be allowed to retain data for more than a fixed amount of time (13 months) for legal reasons (privacy protection).
Is there a practical technique for such situation, allowing to “forget” some old data without breaking immutability ?
A technique that comes to mind would be to use one stream per month, starting with a snapshot of the state aggregated from previous months. That would allow to hard-delete the streams older than 13 months but doesn’t look very practical (especially around the new-month-switch).
What do you think ?