pg.ddx.io pgsql-performance@postgresql.org mailing list archive help / color / mirror / Atom feed From: Josh Berkus <josh@agliodbs.com>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: pgsql-hackers@postgresql.org
Subject: Re: Allow a per-tablespace effective_io_concurrency setting
Date: Wed, 2 Sep 2015 14:31:35 -0700
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On 09/02/2015 02:25 PM, Tomas Vondra wrote:
>
> As I explained, spindles have very little to do with it - you need
> multiple I/O requests per device, to get the benefit. Sure, the DBAs
> should know how many spindles they have and should be able to determine
> optimal IO depth. But we actually say this in the docs:
My experience with performance tuning is that values above 3 have no
real effect on how queries are executed.
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com
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To: pgsql-performance@postgresql.org
Cc: josh@agliodbs.com, tomas.vondra@2ndquadrant.com, pgsql-hackers@postgresql.org
Subject: Re: Allow a per-tablespace effective_io_concurrency setting
In-Reply-To: <55E76AB7.4030306@agliodbs.com>
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