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In which modern MVCC databases can you ask the results of a query if it had been made 1000 transactions before I started this transaction? MVCC is great for dealing with the problems caused by mutability with Concurrency. Datomic takes versioning and immutability a good bit farther than that.

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I guess I read more into the last paragraph than I should have; it portrays the simple problem of read write concurrency as if nobody solved it yet. It was a really bad way for the author to end the post because it confuses what was written before.

Mind you, creating audit / history tables to allow querying of past state is an extremely common and very standard database pattern too. Though I will admit I have encountered systems where more than half the tables were being audit logged so it's interesting to think about a database where that was effectively the default.

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