nothing is ever deleted in an immutable store. a persistent store survives across reboots, but you can delete elements
if you can deal with the consequences, removing deletes makes dealing with concurrency a lot easier
if you can deal with the consequences, removing deletes makes dealing with concurrency a lot easier
A third name for the same thing is "append only".
Immutable on the other hand appears to mean a similar thing both in databases and data structures.
Not the greatest use of terms but that's how I view it.
[1]on-prem, not cloud
However even if the DB doesn't offer that operation, you could use "crypto shredding" where you encrypt the data before putting it in the immutable db and then store the key in some kind of mutable store. (Then delete the key when you want to delete its corresponding data).
There's also this post which describes some other methods of making a Datomic cloud system gdpr compliant: https://vvvvalvalval.github.io/posts/2018-05-01-making-a-dat...