Re: speeding up planning with partitions

From: Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp>
To: "Imai, Yoshikazu" <imai(dot)yoshikazu(at)jp(dot)fujitsu(dot)com>, "'Amit Langote'" <amitlangote09(at)gmail(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, David Rowley <david(dot)rowley(at)2ndquadrant(dot)com>, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, Justin Pryzby <pryzby(at)telsasoft(dot)com>, Pg Hackers <pgsql-hackers(at)postgresql(dot)org>, Jesper Pedersen <jesper(dot)pedersen(at)redhat(dot)com>
Subject: Re: speeding up planning with partitions
Date: 2019-03-20 09:06:40
Message-ID: 3b8f05d6-99ed-1c0b-687c-a01629fccce3@lab.ntt.co.jp
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Imai-san,

On 2019/03/20 17:36, Imai, Yoshikazu wrote:
> On Wed, Mar 20, 2019 at 8:21 AM, Amit Langote wrote:
>> On 2019/03/20 12:15, Imai, Yoshikazu wrote:
>>> [select1024.sql]
>>> \set a random (1, 1024)
>>> select * from rt where a = :a;
>>>
>>> [pgbench]
>>> pgbench -n -f select1024.sql -T 60
>>
>> Thank you.
>>
>> Could you please try with running pgbench for a bit longer than 60 seconds?
>
> I run pgbench for 180 seconds but there are still difference.

Thank you very much.

> 1024: 7,004 TPS
> 8192: 5,859 TPS
>
>
> I also tested for another number of partitions by running pgbench for 60 seconds.
>
> num of part TPS
> ----------- -----
> 128 7,579
> 256 7,528
> 512 7,512
> 1024 7,257 (7274, 7246, 7252)
> 2048 6,718 (6627, 6780, 6747)
> 4096 6,472 (6434, 6565, 6416) (quoted from above (3)'s results)
> 8192 6,008 (6018, 5999, 6007)
>
>
> I checked whether there are the process which go through the number of partitions, but I couldn't find. I'm really wondering why this degradation happens.

Indeed, it's quite puzzling why. Will look into this.

Thanks,
Amit

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Amit Langote 2019-03-20 09:07:23 Re: BUG #15668: Server crash in transformPartitionRangeBounds
Previous Message Amit Langote 2019-03-20 09:06:13 Re: Problem with default partition pruning