Re: index prefetching

Hi,

On 2025-08-06 16:12:53 +0200, Tomas Vondra wrote:
> That's quite possible. What concerns me about using tables like pgbench
> accounts table is reproducibility - initially it's correlated, and then
> it gets "randomized" by the workload. But maybe the exact pattern
> depends on the workload - how many clients, how long, how it correlates
> with vacuum, etc. Reproducing the dataset might be quite tricky.
> 
> That's why I prefer using "reproducible" data sets. I think the data
> sets with "fuzz" seem like a pretty good model. I plan to experiment
> with adding some duplicate values / runs, possibly with two "levels" of
> randomness (global for all runs, and smaller local perturbations).
> [...]
> Yeah, cases like that are interesting. I plan to do some randomized
> testing, exploring "strange" combinations of parameters, looking for
> weird behaviors like that.

I'm just catching up: Isn't it a bit early to focus this much on testing? ISMT
that the patchsets for both approaches currently have some known architectural
issues and that addressing them seems likely to change their performance
characteristics.

Greetings,

Andres Freund