From: Joshua D. Drake <jd@commandprompt.com>
To: Andres Freund <andres@anarazel.de>
To: Rakesh Kumar <rakeshkumar464@mail.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Stephen Frost <sfrost@snowman.net>
Cc: pgsql-general@lists.postgresql.org <pgsql-general@lists.postgresql.org>
Subject: Re: data-checksums
Date: Tue, 9 Jan 2018 12:37:16 -0800
Message-ID: <163ee8df-cae2-484e-5791-c74994d33403@commandprompt.com> (raw)
In-Reply-To: <20180109202259.cpszfiavep42pp6v@alap3.anarazel.de>
References: <trinity-9ae7ee48-40c7-4820-ac76-c53e606435ab-1515520721430@3c-app-mailcom-lxa16>
<20180109184149.ih4ore4c4axwizor@alvherre.pgsql>
<trinity-6e592d6e-7902-4df2-8806-95914ae94d12-1515524644593@3c-app-mailcom-lxa04>
<20180109202259.cpszfiavep42pp6v@alap3.anarazel.de>
On 01/09/2018 12:22 PM, Andres Freund wrote:
> On 2018-01-09 20:04:04 +0100, Rakesh Kumar wrote:
>>>> I also would like to believe that the hit is small, but when PG
>>>> official document writes "noticeable performance penalty", it becomes
>>>> difficult to convince management that the hit is small :-)
>>> Why believe, when you can measure?
>> yup doing that. But I still feel that PG documentation should stay
>> away from such scare mongering. Or did the lawyers write that :)
> So we should rather lie about it having a potential for performance
> impact? Who'd be helped by that?
It isn't a lie, it depends on the workload and hardware. Adjusting the
documentation to say something like the following probably isn't a bad idea:
The use of the data checksum feature may incur a performance penalty.
However, this does depend on your particular workload and provisioned
hardware. It is wise to test the feature based on your specific
requirements.
JD
--
Command Prompt, Inc. || http://the.postgres.company/ || @cmdpromptinc
PostgreSQL centered full stack support, consulting and development.
Advocate: @amplifypostgres || Learn: https://postgresconf.org
***** Unless otherwise stated, opinions are my own. *****
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-general@postgresql.org
Cc: jd@commandprompt.com, andres@anarazel.de, rakeshkumar464@mail.com, alvherre@alvh.no-ip.org, sfrost@snowman.net, pgsql-general@lists.postgresql.org
Subject: Re: data-checksums
In-Reply-To: <163ee8df-cae2-484e-5791-c74994d33403@commandprompt.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox