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From: Charles Nadeau <charles.nadeau@gmail.com>
Date: Mon, 10 Jul 2017 17:48:25 +0200
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 <CADFyZw4UanW5TbFajWKWhN9XcW+8gtCXw+kssHo47Wpr1A=zJw@mail.gmail.com>
Subject: Re: Very poor read performance, query independent
To: Andreas Kretschmer <andreas@a-kretschmer.de>
Cc: pgsql-performance@postgresql.org
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Andreas,

Because the ratio between the Sequential IOPS and Random IOPS is about 29.
Taking into account that part of the data is in RAM, I obtained an
"effective" ratio of about 22.
Thanks!

Charles

On Mon, Jul 10, 2017 at 5:35 PM, Andreas Kretschmer <andreas@a-kretschmer.de
> wrote:

>
>
> Am 10.07.2017 um 16:03 schrieb Charles Nadeau:
>
>> random_page_cost | 22
>>
>
>
> why such a high value for random_page_cost?
>
> Regards, Andreas
>
> --
> 2ndQuadrant - The PostgreSQL Support Company.
> www.2ndQuadrant.com
>
>
>
> --
> Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
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-- 
Charles Nadeau Ph.D.
http://charlesnadeau.blogspot.com/

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<div dir=3D"ltr">Andreas,<div><br></div><div>Because the ratio between the =
Sequential IOPS and Random IOPS is about 29. Taking into account that part =
of the data is in RAM, I obtained an &quot;effective&quot; ratio of about 2=
2.</div><div>Thanks!</div><div><br></div><div>Charles</div></div><div class=
=3D"gmail_extra"><br><div class=3D"gmail_quote">On Mon, Jul 10, 2017 at 5:3=
5 PM, Andreas Kretschmer <span dir=3D"ltr">&lt;<a href=3D"mailto:andreas@a-=
kretschmer.de" target=3D"_blank">andreas@a-kretschmer.de</a>&gt;</span> wro=
te:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-=
left:1px #ccc solid;padding-left:1ex"><br>
<br>
Am 10.07.2017 um 16:03 schrieb Charles Nadeau:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">
random_page_cost | 22 <br>
</blockquote>
<br>
<br>
why such a high value for random_page_cost?<br>
<br>
Regards, Andreas<span class=3D"HOEnZb"><font color=3D"#888888"><br>
<br>
-- <br>
2ndQuadrant - The PostgreSQL Support Company.<br>
<a href=3D"http://www.2ndQuadrant.com" rel=3D"noreferrer" target=3D"_blank"=
>www.2ndQuadrant.com</a><br>
<br>
<br>
<br>
-- <br>
Sent via pgsql-performance mailing list (<a href=3D"mailto:pgsql-performanc=
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rformance</a><br>
</font></span></blockquote></div><br><br clear=3D"all"><div><br></div>-- <b=
r><div class=3D"gmail_signature" data-smartmail=3D"gmail_signature">Charles=
 Nadeau Ph.D.<br><a href=3D"http://charlesnadeau.blogspot.com/" target=3D"_=
blank">http://charlesnadeau.blogspot.com/</a></div>
</div>

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