On Wed, Nov 13, 2024 at 11:19 PM Sutou Kouhei <k...@clear-code.com> wrote: > > Hi, > > In <20241105.174328.1705956947135248653....@clear-code.com> > "Re: Make COPY format extendable: Extract COPY TO format implementations" > on Tue, 05 Nov 2024 17:43:28 +0900 (JST), > Sutou Kouhei <k...@clear-code.com> wrote: > > >> I've further investigated the performance regression, and found out it > >> might be relevant that the compiler doesn't inline the > >> CopyFromTextLikeOneRow() function. It might be worth testing with > >> pg_attribute_always_inline instead of 'inline' as below: > > > > Wow! Good catch! > > > > I've rebased on the current master and updated the v20 and > > v21 patch sets with "pg_attribute_always_inline" not > > "inline". > > > > The v22 patch set is for the v20 patch set. > > (TO/FROM changes are in one commit.) > > > > The v23 patch set is for the v21 patch set. > > (TO/FROM changes are separated for easy to merge only FROM > > or TO part.) > > I've run benchmark on my machine that has "Intel(R) Core(TM) > i7-3770 CPU @ 3.40GHz". > > Summary: > * "pg_attribute_always_inline" is effective for the "COPY > FROM" part > * "pg_attribute_always_inline" may not be needed for the > "COPY TO" part > > > v20-result.pdf: This is the same result PDF attached in > https://www.postgresql.org/message-id/20241008.173918.995935870630354246.kou%40clear-code.com > . This is the base line for "pg_attribute_always_inline" > change. > > v22-result.pdf: This is a new result PDF for the v22 patch > set. > > COPY FROM: > > 0001: The v22 patch set is slower than HEAD. This just > introduces "routine" abstraction. It increases overhead. So > this is expected. > > 0002-0005: The v22 patch set is faster than HEAD for all > cases. The v20 patch set is slower than HEAD for smaller > data. This shows that "pg_attribute_always_inline" for the > "COPY FROM" part is effective on my machine too. > > > COPY TO: > > 0001: The v22 patch set is slower than HEAD. This is > as expected for the same reason as COPY FROM. > > 0002-0004: The v22 patch set is slower than HEAD. (The v20 > patch set is faster than HEAD.) This is not expected. > > 0005: The v22 patch set is faster than HEAD. This is > expected. But 0005 just exports some functions. It doesn't > change existing logic. So it's strange... > > This shows "pg_attribute_always_inline" is needless for the > "COPY TO" part. > > > I also tried the v24 patch set: > * The "COPY FROM" part is same as the v22 patch set > ("pg_attribute_always_inline" is used.) > * The "COPY TO" part is same as the v20 patch set > ("pg_attribute_always_inline" is NOT used.) > > > (I think that the v24 patch set isn't useful for others. So > I don't share it here. If you're interested in it, I'll > share it here.) > > v24-result.pdf: > > COPY FROM: The same trend as the v22 patch set result. It's > expected because the "COPY FROM" part is the same as the v22 > patch set. > > COPY TO: The v24 patch set is faster than the v22 patch set > but the v24 patch set isn't same trend as the v20 patch > set. This is not expected because the "COPY TO" part is the > same as the v20 patch set. > > > Anyway, the 0005 "COPY TO" parts are always faster than > HEAD. So we can use either "pg_attribute_always_inline" or > "inline". > > > Summary: > * "pg_attribute_always_inline" is effective for the "COPY > FROM" part > * "pg_attribute_always_inline" may not be needed for the > "COPY TO" part > > > Can we proceed this proposal with these results? Or should > we wait for more benchmark results?
Thank you for sharing the benchmark test results! I think these results are good for us to proceed. I'll closely look at COPY TO results and review v22 patch sets. Regards, -- Masahiko Sawada Amazon Web Services: https://aws.amazon.com
