Re: problems with making relfilenodes 56-bits

Hi,

On 2022-09-30 15:36:11 +0530, Dilip Kumar wrote:
> I have done some testing around this area to see the impact on WAL
> size especially when WAL sizes are smaller, with a very simple test
> with insert/update/delete I can see around an 11% increase in WAL size
> [1] then I did some more test with pgbench with smaller scale
> factor(1) there I do not see a significant increase in the WAL size
> although it increases WAL size around 1-2%. [2].

I think it'd be interesting to look at per-record-type stats between two
equivalent workload, to see where practical workloads suffer the most
(possibly with fpw=off, to make things more repeatable).

I think it'd be an OK tradeoff to optimize WAL usage for a few of the worst to
pay off for 56bit relfilenodes. The class of problems foreclosed is large
enough to "waste" "improvement potential" on this.

Greetings,

Andres Freund