Re: Block-level CRC checks - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Block-level CRC checks
Date
Msg-id 23211.1222875404@sss.pgh.pa.us
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In response to Re: Block-level CRC checks  ("Jonah H. Harris" <jonah.harris@gmail.com>)
Responses Re: Block-level CRC checks
Re: Block-level CRC checks
Re: Block-level CRC checks
Re: Block-level CRC checks
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"Jonah H. Harris" <jonah.harris@gmail.com> writes:
> On Wed, Oct 1, 2008 at 10:27 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Your optimism is showing ;-).  XLogInsert routinely shows up as a major
>> CPU hog in any update-intensive test, and AFAICT that's mostly from the
>> CRC calculation for WAL records.

> I probably wouldn't compare checksumming *every* WAL record to a
> single block-level checksum.

No, not at all.  Block-level checksums would be an order of magnitude
more expensive: they're on bigger chunks of data and they'd be done more
often.
        regards, tom lane


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