Why is it called "immutable" iso "persistent"?
Sure, some academics used the term for a class of in-memory data structures too, and it got taken over in some programming circles, but it's a niche term at best. Now, so far so good, but using that term for databases might be maximally confusing. After all, isn't a database's primary purpose to persist data? Then, aren't all databases persistent? Oh, no, the author meant that other meaning of "persistent" that many people aren't familiar with.
I think the author made the right call :-)
(I know that immutable and persistent aren't the same thing: you can make an immutable data structure that isn't persistent in that it doesn't reuse data - but it's the best we got)
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...