At 2014-12-26 13:11:43 -0500, bruce@momjian.us wrote:
>
> Is this something that could potentially change the data stored on
> disk? Does pg_upgrade need to check for changes in this area? Is the
> detection exposed by pg_controldata? Could this affect running the
> data directory on a different CPU?
No to all.
Subsequent to Heikki's change (already in master) to use the CRC-32C
algorithm (instead of the earlier mistakenly-reflected-but-not-quite
one), both the slice-by-8 software implementation posted earlier and
the SSE4.2 CRC32* instructions will compute exactly the same value.
(Yes, I have verified this in both cases.)
-- Abhijit
