On Mon, Aug 7, 2023 at 3:16 PM David Rowley <dgrowle...@gmail.com> wrote: > > On Wed, 2 Aug 2023 at 13:35, David Rowley <dgrowle...@gmail.com> wrote: > > So, it looks like this item can be closed off. I'll hold off from > > doing that for a few days just in case anyone else wants to give > > feedback or test themselves. > > Alright, closed.
IIUC the problem with multiple concurrent COPY is not resolved yet. I've run the same benchmark that I used for the first report: * PG15 (cb2ae5741f) nclients = 1, execution time = 15.213 nclients = 2, execution time = 9.470 nclients = 4, execution time = 6.508 nclients = 8, execution time = 4.526 nclients = 16, execution time = 3.788 nclients = 32, execution time = 3.837 nclients = 64, execution time = 4.286 nclients = 128, execution time = 4.388 nclients = 256, execution time = 4.333 * PG16 (67a007dc0c) nclients = 1, execution time = 14.494 nclients = 2, execution time = 12.962 nclients = 4, execution time = 17.757 nclients = 8, execution time = 10.865 nclients = 16, execution time = 7.371 nclients = 32, execution time = 4.929 nclients = 64, execution time = 2.212 nclients = 128, execution time = 2.020 nclients = 256, execution time = 2.196 The result of nclients = 1 became better thanks to recent fixes, but there still seems to be the performance regression at nclient = 2~16 (on RHEL 8 and 9). Andres reported[1] that after changing MAX_BUFFERED_TUPLES to 5000 the numbers became a lot better but it would not be the solution, as he mentioned. Regards, [1] https://www.postgresql.org/message-id/20230711185159.v2j5vnyrtodnwhgz%40awork3.anarazel.de -- Masahiko Sawada Amazon Web Services: https://aws.amazon.com