Postgres used to have time travel -- it is relatively easy feature to build on a MVCC storage -- but it was deprecated in 6.2 and then removed [1]. Performance

Postgres used to have time travel -- it is relatively easy feature to build on a MVCC storage -- but it was deprecated in 6.2 and then removed [1]. Performance was one reason listed, as was space usage. It's easy to see why. For example, modern Postgres versions will in some cases reclaim dead tuples for new data, thus "cheating" by bypassing MVCC. If Postgres had to support time travel, such optimizations wouldn't be possible. I seem to remember developers talking about adding time travel back now that the codebase is better (and better understood) and it could be redesigned around current techniques. It's a cool feature to have. [1] https://www.postgresql.org/docs/6.3/c0503.htm https://www.postgresql.org/docs/6.3/c0503.htm