MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8;
 format=flowed
Date: Mon, 04 May 2015 14:14:01 +0200
From: Jan Lentfer <Jan.Lentfer@web.de>
To: <pgsql-admin@postgresql.org>
Subject: Re: =?UTF-8?Q?pg=5Fdump=20and=20pg=5Frestore=20with=20mul?=
 =?UTF-8?Q?tiple=20streams=20does=20Not=20seem=20to=20improve=20overall=20?=
 =?UTF-8?Q?times?=
In-Reply-To: 
 <CAOR=d=1OJQfkmygTDL_eVWMAEkFJbsvWb3=+QSf+g5Ct8T1ToQ@mail.gmail.com>
References: <em5e30e63a-661c-44ad-8996-601c945efc8b@oyster-creek>
 <CAOR=d=1OJQfkmygTDL_eVWMAEkFJbsvWb3=+QSf+g5Ct8T1ToQ@mail.gmail.com>
Message-ID: <d2d0b6691081e6e714f61d9d9db39a13@imap.lan.net>
User-Agent: Roundcube Webmail/0.7.2
Content-Transfer-Encoding: quoted-printable
Precedence: bulk
Sender: pgsql-admin-owner@postgresql.org

Am 2015-05-01 17:49, schrieb Scott Marlowe:
> On Fri, May 1, 2015 at 9:16 AM, Susan K. McClure <smcclure@rice.edu
> [1]> wrote:
>
>> Running postgresql 9-4 on REHL 7 system. I am trying to speed up
>> pg_dump and pg_restore by
>> using a postgresql.conf with various performance options set, and
>> the --jobs option to force multiple
>> streams.=C2=A0 But various tests, with various "--jobs=3D" =C2=A0numbers=
 only
>> achieve at most a 1 minute improvement
>> in elapsed time versus doing pg_dump or pg_restore with no "--jobs"
>> option and no postgresql.conf with performance
>> options.=C2=A0 Am I missing some key option(s) to improve things??=C2=A0
>> =C2=A0
>> The DB in question is ~25GB.=C2=A0 The processor has 24 Cpus, 12 cores
>> =C2=A0
>> I have tried with "--jobs =3D 8, 12, and 20"=C2=A0 with little or no
>> discernible improvements.
>
> So have you tried 2 jobs first? Id see how 1, 2, 3, 4 etc work. See=20
> if
> 2 is faster than 1, then 3 faster than 2 etc.
>
> Most of the time, unless youve got a really fast IO subsystem
> increasing the --jobs doesnt make a big difference as a lot of the
> work is sequential. Also on restores I think the extra jobs part only
> kicks in for index builds.

It does parallel COPY, too.

Jan


--=20
Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-admin