Surprisingly, neither Datomic nor XTDB support branching. See: https://blog.danieljanus.pl/datomic-forking-the-past/
replyI actually built my own immutable database which does support branching (see profile), so it seems like a huge miss that these ones don't. It's pretty much the main reason I would want an immutable database.
Wait, this statement seems way too strong.
replyThe linked article points out that Datomic doesn't support branching from the past. It absolutely does support branching, and I've built entire test suites that way.
From a cursory glance, I'd say Datomic does exactly what the original parent article is discussing. It works great and it's super convenient.
If each "branch" is read only, it's not a branch at all. The entire idea of branching implies that you can make changes on one branch, then switch to another branch and make changes to it. They start from the same point and grow in different directions, as the metaphor of branches on a tree depicts.
replyIt appears that Datahike [0] is a Datomic workalike that supports branching. I haven’t tried it out myself (yet), but the documentation suggests it’s possible [1].
replyThat said, I’m adding xitdb to the list of tech to try out. Thank you for building it!
Oh, and thanks for linking to my article :-)