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.
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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.
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.
