On Wed, Aug 28, 2024 at 10:58 AM Robert Haas <robertmhaas@gmail.com> wrote:
> Ever since I read
> https://15721.courses.cs.cmu.edu/spring2020/papers/22-costmodels/p204-leis.pdf
> I have believed that the cardinality misestimate leading to nested
> loop plans is just because we're doing something dumb.
> We don't even have an option to turn off that kind of join, and we
> could probably avoid a lot of pain if we did. This, too, is mostly
> separate from the topic of this thread, but I just can't believe we've
> chosen to do literally nothing about this given that we all know this
> specific thing hoses everybody, everywhere, all the time.
I couldn't agree more. I was really annoyed when your proposal was shot down.
It's an unusually clear-cut issue. Tying it to much broader and much
more complicated questions about how we model risk was a mistake.
--
Peter Geoghegan
