On Mon, Oct 14, 2024 at 10:20 PM David Rowley <dgrowle...@gmail.com> wrote:
> Yeah, I think any effort to change the default value for this setting > would require some analysis to prove that the newly proposed default > is a more suitable setting than the current default. I mean, why 1.2 and > not 1.1 or 1.3? Where's the evidence that 1.2 is the best value > for this? > As I said, I was just throwing that 1.2 number out there. It felt right, although perhaps a tad high (which seems right as we keep things very conservative). I agree we should make a best effort to have an accurate, defendable default. We all know (I hope) that 4.0 is wrong for SSDs. > I don't think just providing evidence that random read times are closer to > sequential read times on SSDs are closer than they are with > HDDs is going to be enough. ... > It would be nice to have this as a script so that other people could > easily run it on their hardware to ensure that random_page_cost we > choose as the new default is representative of the average hardware. Heh, this is starting to feel like belling the cat (see https://fablesofaesop.com/belling-the-cat.html) Remember this is still just a default, and we should encourage people to tweak it themselves based on their own workloads. I just want people to start in the right neighborhood. I'll see about working on some more research / generating a script, but help from others is more than welcome. Cheers, Greg
