Many readers will be aware that an unusually high number of features have been reverted from the PostgreSQL 19 branch after the beta period began. Having some reverts is not unusual, and maybe one per cycle could be expected. But this time around, about 8 to 10 significant features, depending on how you count, have been reverted, some of them quite late in the beta period. The author, a developer or committer of some of the affected features, reflects on what happened, offering opinions that are still preliminary.
The causes are likely a combination of factors that differ for each feature. The author admits the code may not have been good enough, and that the team may not have done a good enough job. It may also have been coincidence: the project had been on a good roll and attempted several features that proved too hard to finish in time. Some features had significant architectural defects that would have been difficult to fix quickly during beta. Others suffered from a long tail of relatively harmless edge-case issues that, in past cycles, would have surfaced later and been fixed gradually over subsequent years.
LLM-assisted code review has changed that timeline. These issues are now found much faster, leaving developers with a list of around forty defect reports. Even if each needs only a small fix, the fixed overhead of handling each one adds up and time runs out. Most affected features were written long before such review tools were useful, so the effective quality bar has risen since they were committed. The author argues this is not due to "vibe coding," since the code predates that possibility.
The situation was also worsened by the security crisis dubbed the "Vulnpocalypse," which pulled many senior developers onto security fixes from April through August. As a result, the usual extra review and testing during beta was reduced and only resumed later, explaining why many issues surfaced so late. The author believes that with about two more months, many of the smaller issues could have been addressed, but the community chose to keep to the release schedule rather than delay.
Source: Hacker News · Summarized by HeadlinesBriefing