From: Stephen Frost <sfrost@snowman.net>
To: Rakesh Kumar <rakeshkumar464@mail.com>
Cc: pgsql-general@lists.postgresql.org <pgsql-general@lists.postgresql.org>
Subject: Re: data-checksums
Date: Tue, 9 Jan 2018 12:54:10 -0500
Message-ID: <20180109175410.GH2416@tamriel.snowman.net> (raw)
In-Reply-To: <trinity-a78f07c6-1bc0-4bd4-8cd7-2c52a7384eb1-1515519726939@3c-app-mailcom-lxa01>
References: <trinity-a78f07c6-1bc0-4bd4-8cd7-2c52a7384eb1-1515519726939@3c-app-mailcom-lxa01>
Greetings,
* Rakesh Kumar (rakeshkumar464@mail.com) wrote:
> --data-checksums
> Use checksums on data pages to help detect corruption by the I/O system that would otherwise be silent. Enabling checksums may incur a noticeable performance penalty. This option can only be set during initialization, and cannot be changed later. If set, checksums are calculated for all objects, in all databases.
> ====
>
> If I understand it correctly, the performance penalty is when the blocks are written to the disk by the background writer and/or during checkpoint. Given that the process is async and application does not wait on it, is the performance penalty really a big concern.
There's also a hit when pages are read back in, since we need to
calculate the checksum and verify it hasn't changed.
That said, imv anyway, the performance hit is small and having checksums
is well worth it.
Thanks!
Stephen
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To: pgsql-general@postgresql.org
Cc: sfrost@snowman.net, rakeshkumar464@mail.com, pgsql-general@lists.postgresql.org
Subject: Re: data-checksums
In-Reply-To: <20180109175410.GH2416@tamriel.snowman.net>
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