Re: Page Checksums

On Mon, Dec 19, 2011 at 09:34:51AM -0500, Robert Haas wrote:
> On Mon, Dec 19, 2011 at 9:14 AM, Stephen Frost <sfrost(at)snowman(dot)net> wrote:
> > * Aidan Van Dyk (aidan(at)highrise(dot)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.

Would you be so kind as to elucidate this a bit?

Cheers,
David.
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