Re: Page Checksums

On Sun, Dec 18, 2011 at 12:19:32PM +0200, Heikki Linnakangas wrote:
> On 18.12.2011 10:54, David Fetter wrote:
> >On Sun, Dec 18, 2011 at 10:14:38AM +0200, Heikki Linnakangas wrote:
> >>On 17.12.2011 23:33, David Fetter wrote:
> >>>If this introduces new failure modes, please detail, and preferably
> >>>demonstrate, just what those new modes are.
> >>
> >>Hint bits, torn pages ->  failed CRC. See earlier discussion:
> >>
> >>http://archives.postgresql.org/pgsql-hackers/2009-11/msg01975.php
> >
> >The patch requires that full page writes be on in order to obviate
> >this problem by never reading a torn page.
> 
> Doesn't help. Hint bit updates are not WAL-logged.

What new failure modes are you envisioning for this case?  Any way to
simulate them, even if it's by injecting faults into the source code?

Cheers,
David.
-- 
David Fetter <david@fetter.org> http://fetter.org/
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