Re: WIP checksums patch

On Fri, 2012-09-14 at 17:58 -0700, Jeff Davis wrote:
> This is just a rebased version of the patch by Simon here:
> 
> http://archives.postgresql.org/message-id/CA
> +U5nMKw_GBs6qQ_Y8-RjGL1V7MVW2HWBHartB8LoJhnPfxL8g@mail.gmail.com

Another thing I noticed about the design of this patch:

It looks like the checksum will usually be wrong in a backup block in
WAL, because it writes the backup block before calculating the checksum
(which isn't done until the time the block is written out).

I think that's OK, because it's still protected by the WAL CRC, and
there's no expectation that the checksum is correct in shared buffers,
and the correct checksum should be set on the next checkpoint. Just an
observation.

Regards,Jeff Davis