zlacker

Legacy reasons. The idea was that you wouldn't need a WAL because the table itself is the log. And then you could support time-travel queries if you never cleaned up the expired tuples.

>>apavlo+(OP)
Is MVCC actually superior by some other considerations? Less lock contentions, transactional DML.

>>apavlo+(OP)
_And_ it wasn't even originally designed to be used for concurrency control at all...

>>riku_i+vm
The problem is not mvcc but postgres’ implementation details of it.

>>maskli+WH
In what way? I didn't see anything obviously improper when I learned how serialization isolation worked.

>>Max-Ga+nI
A delicated full vacuum process that need full locking, how little isolation between tables, etc

Lots of the pain point have been mitigated in the last ten years. It is now as simple as other comparable complex db can go (i.e. Not simple, but you can't find better product)

>>Max-Ga+nI
TFA covers its issues? It’s specifically compares postgres’ to other implementations’ (oracle and mysql).

>>maskli+jD1
Also the paper linked from TFA goes into the various implementation options in more detail: https://db.cs.cmu.edu/papers/2017/p781-wu.pdf