The reverts will continue until morale improves

PostgreSQL core team member Peter Eisentraut has penned a blog post discussing the significant number of features that have been reverted in the upcoming PostgreSQL 19 release since the beta period commenced. Some of the reverted features possessed serious architectural flaws that would have been challenging to rectify swiftly during the beta stage.

However, there was also a substantial number of relatively minor issues related to various edge cases. Historically, many of these issues would have remained undiscovered until later stages, and they would have been addressed gradually over a span of five years. With the advent of LLM-assisted code review, these types of problems can be identified much more rapidly, resulting in a list of approximately forty defect reports.

Even if each issue necessitates an average of three lines of code to resolve, there is an additional fixed overhead involved in addressing each of these matters, and eventually, time constraints become a limiting factor. Most, if not all, of the reverted features were developed quite some time ago, before the benefits of LLM-assisted code review were fully realized.

Consequently, the quality bar has been raised post facto, making it more difficult to maintain the original level of quality. Unless the effectiveness of LLM-assisted code review continues to improve at its current pace, this predicament should resolve itself for future development cycles. Eisentraut suggests that this situation is not primarily attributable to "vibe coding," as the affected code was written well before the concept of this phenomenon emerged. LWN covered the unprecedented volume of bug fixes required for PostgreSQL 19 features in September.