postgres 19 ships late and lighter, because the reviewers got better

postgresql 19 was meant to land around the start of october. it is now expected around 19 november, and somewhere between eight and ten significant features have been reverted out of it during beta, to come back in version 20. the most visible casualty is sql/pgq, the 2023 addition to the sql standard for querying graphs of nodes and edges.

peter eisentraut, a long time committer who wrote some of the reverted code, gave his own reasons on his blog. senior developers spent april to august on a wave of security fixes instead of the usual beta testing. some features were simply too hard to finish. and llm-assisted review now turns up flaws in days that used to take years to surface. the code did not get worse; the bar for shipping it moved after it was written. he is clear this is not about code written by ai, which most of these features predate.