Re: Sort functions with specialized comparators - Mailing list pgsql-hackers

From Stepan Neretin
Subject Re: Sort functions with specialized comparators
Date
Msg-id CAN-sa+DpcDHcWsd8pOa0EjdjmA8LFdsWzxgvigDtd+NMFTbrGQ@mail.gmail.com
Whole thread Raw
In response to Re: Sort functions with specialized comparators  ("Andrey M. Borodin" <x4mmm@yandex-team.ru>)
List pgsql-hackers


On Tue, Jul 16, 2024 at 1:47 AM Andrey M. Borodin <x4mmm@yandex-team.ru> wrote:


> On 15 Jul 2024, at 12:52, Stepan Neretin <sncfmgg@gmail.com> wrote:
>
>
> I run benchmark with my patches:
> ./pgbench -c 10 -j2 -t1000 -d postgres
>
> pgbench (18devel)
> starting vacuum...end.
> transaction type: <builtin: TPC-B (sort of)>
> scaling factor: 10
> query mode: simple
> number of clients: 10
> number of threads: 2
> maximum number of tries: 1
> number of transactions per client: 1000
> number of transactions actually processed: 10000/10000
> number of failed transactions: 0 (0.000%)
> latency average = 1.609 ms
> initial connection time = 24.080 ms
> tps = 6214.244789 (without initial connection time)
>
> and without:
> ./pgbench -c 10 -j2 -t1000 -d postgres
>
> pgbench (18devel)
> starting vacuum...end.
> transaction type: <builtin: TPC-B (sort of)>
> scaling factor: 10
> query mode: simple
> number of clients: 10
> number of threads: 2
> maximum number of tries: 1
> number of transactions per client: 1000
> number of transactions actually processed: 10000/10000
> number of failed transactions: 0 (0.000%)
> latency average = 1.731 ms
> initial connection time = 15.177 ms
> tps = 5776.173285 (without initial connection time)
>
> tps with my patches increase. What do you think?


Hi Stepan!

Thank you for implementing specialized sorting and doing this benchmarks.
I believe it's a possible direction for good improvement.
However, I doubt in correctness of your benchmarks.
Increasing TPC-B performance from 5776 TPS to 6214 TPS seems too good to be true.


Best regards, Andrey Borodin.

Yes... I agree.. Very strange.. I restarted the tps measurement and see this:

tps = 14291.893460 (without initial connection time)  not patched
tps = 14669.624075 (without initial connection time)  patched

What do you think about these measurements?
Best regards, Stepan Neretin.

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