Horton

Re: Page Checksums

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Stephen Frost <sfrost@snowman.net>
Cc: Aidan Van Dyk <aidan@highrise.ca>, Josh Berkus <josh@agliodbs.com>, pgsql-hackers@postgresql.org
Date: 2011-12-19T14:34:51Z
Lists: pgsql-hackers 
On Mon, Dec 19, 2011 at 9:14 AM, Stephen Frost <sfrost@snowman.net> wrote:
> * Aidan Van Dyk (aidan@highrise.ca) wrote:
>> But the scary part is you don't know how long *ago* the crash was.
>> Because a hint-bit-only change w/ a torn-page is a "non event" in
>> PostgreSQL *DESIGN*, on crash recovery, it doesn't do anything to try
>> and "scrub" every page in the database.
>
> Fair enough, but, could we distinguish these two cases?  In other words,
> would it be possible to detect if a page was torn due to a 'traditional'
> crash and not complain in that case, but complain if there's a CRC
> failure and it *doesn't* look like a torn page?

No.

-- 
Robert Haas
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