| From: | Thomas Munro <thomas(dot)munro(at)gmail(dot)com> |
|---|---|
| To: | Ranier Vilela <ranier(dot)vf(at)gmail(dot)com> |
| Cc: | Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Parallel Seq Scan vs kernel read ahead |
| Date: | 2020-05-21 00:02:36 |
| Message-ID: | CA+hUKGKnBHSN5towU+k8pQJnM8cWUwYKnG8BzpPRQAnWunp5yQ@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Thu, May 21, 2020 at 11:51 AM Ranier Vilela <ranier(dot)vf(at)gmail(dot)com> wrote:
> Em qua., 20 de mai. de 2020 às 20:48, Thomas Munro <thomas(dot)munro(at)gmail(dot)com> escreveu:
>> On Thu, May 21, 2020 at 11:15 AM Ranier Vilela <ranier(dot)vf(at)gmail(dot)com> wrote:
>> > postgres=# set max_parallel_workers_per_gather = 0;
>> > Time: 227238,445 ms (03:47,238)
>> > postgres=# set max_parallel_workers_per_gather = 1;
>> > Time: 138027,351 ms (02:18,027)
>>
>> Ok, so it looks like NT/NTFS isn't suffering from this problem.
>> Thanks for testing!
>
> Maybe it wasn’t clear, the tests were done with your patch applied.
Oh! And how do the times look without it?
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