OK, I've updated the PR with a benchmark (in the main directory). On this benchmark I'm seeing about a 24% reduction in "user" CPU time, and a 8% reduction in "system" CPU time. (Almost no reduction in wall-clock time.)
Jeroen On Fri, 10 Feb 2023 at 11:32, Jeroen Vermeulen <jtv...@gmail.com> wrote: > Here's the patch (as a PR just to make it easy to read): > https://github.com/jtv/postgres/pull/1 > > I don't have an easily readable benchmark yet, since I've been timing the > potential impact on libpqxx. But can do that next. > > > Jeroen > > On Fri, Feb 10, 2023, 11:26 Bharath Rupireddy < > bharath.rupireddyforpostg...@gmail.com> wrote: > >> On Fri, Feb 10, 2023 at 3:43 PM Jeroen Vermeulen <jtv...@gmail.com> >> wrote: >> > >> > Would there be interest in a variant of PQgetCopyData() that re-uses >> the same buffer for a new row, rather than allocating a new buffer on each >> iteration? >> > >> > I tried it on a toy benchmark, and it reduced client-side CPU time by >> about 12%. (Less of a difference in wall-clock time of course; the client >> was only using the CPU for a bit over half the time.) >> >> Interesting. It might improve logical replication performance too as >> it uses COPY protocol. >> >> Do you mind sharing a patch, test case that you used and steps to >> verify the benefit? >> >> -- >> Bharath Rupireddy >> PostgreSQL Contributors Team >> RDS Open Source Databases >> Amazon Web Services: https://aws.amazon.com >> >
