Versioning: Is this technology used in DBMS other than spatial?
What you are describing seems really similar to MMVC- https://en.wikipedia.org/wiki/Multiversion_concurrency_control Where different clients can have a different "view" or "version" of the same database, and edits done withing a transaction cannot be seen by other sessions until they decide so by executing "COMMIT".

That concept is not exclusive to spatial databases (the wiki cites a 1981 paper as one of the first descriptions of it: https://en.wikipedia.org/wiki/Multiversion_concurrency_control#cite_note-3 ) but the concept has to be older than that. And while I see some special needs and implementations for extra dimensions, the essentials would be the same.

The implementation, of course, can vary widely from engine to engine. Git, even if not a database, it has to implement concurrency control in a particular way, and that will be completely different to how postgres does it. If then we go to distributed databases, we arrive to the wild west of keeping consistency thought heterogenous systems over the net. You want an implementation that is performant for the most useful cases, and all optimizations imply a trade off for operations considered not as important. One that is fast for small transaction sizes may be too expensive or unbearable for large edits. Also, different database engines interpret thing like consistency levels on its own way.

The good news is that with the rise of open-source database systems, you do not need to read large manuals anymore to understand what is happening internally- you can read the source code directly yourself and understand how those are written. For example, for Innodb:


https://www.percona.com/live/mysql-conference-2013/sessions/innodb-journey-core
https://github.com/mysql/mysql-server/blob/5.7/storage/innobase/row/row0undo.cc