Hi, On 2021-10-25 18:38:40 -0600, Michael Lewis wrote: > On Mon, Oct 25, 2021, 5:36 PM Andres Freund <andres@xxxxxxxxxxx> wrote: > If your hot data set is actually larger than s_b, I'd recommend trying a > larger s_b. It's plausible that a good chunk of lock contention is from > that. > How much larger might you go? I've seen s_b in the ~700GB range being a considerable speedup over lower values quite a few years ago. I don't see a clear cut upper boundary. The one thing this can regress measurably is the speed of dropping / truncating tables. > Any write ups on lock contention as it relates to shared buffers? I don't have a concrete thing to point you to, but searching for NUM_BUFFER_PARTITIONS might point you to some discussions. > How impactful might huge pages (off, transparent or on) be to the use of > shared buffers and the related locking mechanism? Using huge pages can *hugely* help performance-wise. Not directly by relieving postgres-side contention however (it does reduce cache usage somewhat, but it's mainly really just the frequency of TLB misses that makes the difference). Greetings, Andres Freund
