Re: speedup COPY TO for partitioned table. - Mailing list pgsql-hackers

On Mon, Mar 31, 2025 at 4:05 PM Kirill Reshke <reshkekirill@gmail.com> wrote:
>
> Hi!
> I reviewed v7. Maybe we should add a multi-level partitioning case
> into copy2.sql regression test?
>

sure.

> I also did quick benchmarking for this patch:
>
> ==== DDL
>
>  create table ppp(i int) partition by range (i);
>
> genddl.sh:
>
> for i in `seq 0 200`; do echo "create table p$i partition of ppp for
> values from ( $((10 * i)) ) to ( $((10 * (i + 1))) ); "; done
>
> === insert data data:
> insert into ppp select i / 1000  from generate_series(0, 2000000)i;
>
> === results:
>
>
> for 2000001 rows speedup is 1.40 times : 902.604 ms (patches) vs
> 1270.648 ms (unpatched)
>
> for 4000002 rows speedup is 1.20 times : 1921.724 ms (patches) vs
> 2343.393 ms (unpatched)
>
> for 8000004 rows speedup is 1.10 times : 3932.361 ms (patches) vs
> 4358.489ms (unpatched)
>
> So, this patch indeed speeds up some cases, but with larger tables
> speedup becomes negligible.
>

Thanks for doing the benchmark.