Re: New CRC algorithm: Slicing by 8

On Sun, 2006-10-22 at 18:06 -0400, Tom Lane wrote:

> These numbers are um, not impressive.  Considering that a large fraction
> of our WAL records are pretty short, the fact that slice8 consistently
> loses at short buffer lengths is especially discouraging.  Much of that
> ground could be made up perhaps with tenser coding of the initialization
> and finalization code, but it'd still not be worth taking any legal risk
> for AFAICS.

It doesn't look good for SB8, does it? Nor for gcc4.1 either.

Presumably Intel themselves will have some come-back, but I'm not sure
what they'll so to so many conclusive tests.

Instead, I'd like to include a parameter to turn off CRC altogether, for
heavily CPU bound operations and the WAL drive on trustworthy hardware.

wal_checksum = off

--  Simon Riggs              EnterpriseDB   http://www.enterprisedb.com