On Sun, Apr 5, 2026 at 3:57 AM Andrei Lepikhov <[email protected]> wrote: > Looking back at the pg_plan_advice development cycle, I don’t see many > discussions about the design. It seems unusual given how complex the > planner's structure is. It makes sense to follow the typical way and let > it serve out of the contrib for some time and see if it works well. > > Introducing such a module into the core would effectively cancel > alternative solutions, as seen with PGSS. Therefore, it is important to > ensure the code is well-designed before proceeding. Do you agree?
I don't know how anyone could disagree with the idea that PostgreSQL code should be well-designed, but that doesn't mean that I agree that your particular design criticism is fair, and I definitely don't. As for the amount of design discussion on the mailing list, I was disappointed in that, too. In addition to posting to the list, I privately asked numerous people to help review and test. Some did, but on the whole, I was expecting a more vigorous debate and a lot of people telling me what an idiot I am. Instead, the most common feedback I got was some form of "can you ship it right now, please?". That probably has less to do with the design being good (although I believe that it is) or my code being good (although I hope that it is) than with people just really wanting PostgreSQL to have something of this sort. So I am somewhat afraid that this will turn out to have more problems than anyone has noticed so far, and maybe for reasons that will feel dumb in hindsight. But on March 12th, I asked myself whether more people were going to be unhappy if I committed pg_plan_advice this release cycle or if I didn't, and my educated guess was the latter, so I committed it. If that turns out to have been the wrong call, then I apologize to the whole community in advance. But I do not apologize for the fact that pg_plan_advice tries to interpret plan trees -- which I personally think is one of the best design decisions I have ever made while hacking on PostgreSQL -- or that it can't interpret the variant ones that your extension produces. -- Robert Haas EDB: http://www.enterprisedb.com
