Re: Page Checksums

Excerpts from Stephen Frost's message of lun dic 19 11:18:21 -0300 2011:
> * Aidan Van Dyk (aidan(at)highrise(dot)ca) wrote:
> > #) Anybody investigated putting the CRC in a relation fork, but not
> > right in the data block? If the CRC contains a timestamp, and is WAL
> > logged before the write, at least on reading a block with a wrong
> > checksum, if a warning is emitted, the timestamp could be looked at by
> > whoever is reading the warning and know tht the block was written
> > shortly before the crash $X $PERIODS ago....
>
> I do like the idea of putting the CRC info in a relation fork, if it can
> be made to work decently, as we might be able to then support it on a
> per-relation basis, and maybe even avoid the on-disk format change..
>
> Of course, I'm sure there's all kinds of problems with that approach,
> but it might be worth some thinking about.

I think the main objection to that idea was that if you lose a single
page of CRCs you have hundreds of data pages which no longer have good
CRCs.

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Álvaro Herrera <alvherre(at)commandprompt(dot)com>
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