On Sat, Feb 19, 2022 at 6:34 PM Andrey Borodin <x4...@yandex-team.ru> wrote: > There's feature freeze approaching again. I see that you are working on > moving SLRUs to buffer pools, but it is not clear to which PG version it will > land. And there is 100% consensus that first patch is useful and helps to > prevent big issues. Maybe let's commit 1'st step without lifting default > xact_buffers limit? Or 1st patch as-is with any simple technique that > prevents linear search in SLRU buffers.
Hi Andrey, Yeah, the SLRU/buffer pool thing would be complete enough to propose for 16 at the earliest. I posted the early prototype to see what sort of reaction the concept would get before doing more work; I know others have investigated this topic too... maybe it can encourage more patches, experimental results, ideas to be shared... but this is not relevant for 15. Back to this patch: assuming we can settle on a good-enough-for-now replacement algorithm, do we want to add this set of 7 GUCs? Does anyone else want to weigh in on that? Concretely, this patch adds: multixact_offsets_buffers multixact_members_buffers subtrans_buffers notify_buffers serial_buffers xact_buffers commit_ts_buffers I guess the people at https://ottertune.com/blog/postgresql-knobs-list/ would be happy if we did. Hopefully we'd drop the settings in a future release once we figure out the main buffer pool thing (or some other scheme to automate sizing).
