On Wed, Nov 19, 2025 at 2:56 PM Masahiko Sawada <[email protected]> wrote: > > On Thu, Nov 13, 2025 at 7:17 PM Ajin Cherian <[email protected]> wrote: > > > > On Thu, Nov 13, 2025 at 8:49 AM Masahiko Sawada <[email protected]> > > wrote: > > > > > > On Mon, Nov 10, 2025 at 7:37 PM Ajin Cherian <[email protected]> wrote: > > > > > > > > On Tue, Nov 11, 2025 at 2:19 PM Amit Kapila <[email protected]> > > > > wrote: > > > > > > > > > > In the commit message, you mentioned: "Performance tests show it's > > > > > faster than the COPY (SELECT ...) TO variant as it avoids the > > > > > overheads of query processing and sending results to the COPY TO > > > > > command.". Can you share the performance data to substantiate this > > > > > point? > > > > > > > > > > > > > This was based on the tests done in the original thread [1] and [2] > > > > > > Thank you for working on this item. I think it's a good follow-up > > > patch for commit 4bea91f. > > > > > > Have you conducted any performance tests with logical replication > > > setup? I've measured normal COPY TO cases but I think it would be > > > worth checking how much the performance increase we can see in logical > > > replication setup too. > > > > > Thanks for your interest in this patch. > > I've tested the same setup as mentioned in [1] but with 10 tables and > > 500 records each and measuring the total time it would take for all > > the tablesync workers to finish sync (from log timings). > > On the average: > > Without patch > > Tablesync time: 185.4 ms > > Average COPY command times: 1.4168 ms > > > > With patch > > Tablesync time: 172.2 ms (7% improvement) > > Average COPY command times: 0.633 ms > > > > The improvement in performance is smaller as the table size increases. > > There is better improvement for smaller tables. > > Attaching my test scripts as well. > > > > Thank you for the test! I've also done some performance tests and got > similar results. > > The patch is pretty simple and looks good to me. I'll push the patch, > barring objections.
Pushed. Regards, -- Masahiko Sawada Amazon Web Services: https://aws.amazon.com
