Re: Maybe we should reduce SKIP_PAGES_THRESHOLD a bit?

On 12/17/24 18:52, Robert Haas wrote:
> On Tue, Dec 17, 2024 at 12:06 PM Melanie Plageman
> <melanieplageman@gmail.com> wrote:
>> I think your tests show SKIP_PAGES_THRESHOLD has dubious if any
>> benefit related to readahead. But the question is if we care about it
>> for advancing relfrozenxid for small tables.

Yeah, although I'm a bit hesitant to draw such clear conclusion from one
set of benchmarks on one machine (or two, but both with flash). I would
not be surprised if the results were less clear on other types of
storage (say, something like EBS).

> 
> It seems like relfrozenxid advancement is really only a problem for
> big tables. If the table is small, the eventual aggressive vacuum
> doesn't cost that much.
> 

Yeah, I agree with this.


regards

-- 
Tomas Vondra