I will just add a TODO item and we can hit it for 7.2.
> On Wed, Feb 28, 2001 at 04:53:09PM -0500, Tom Lane wrote:
> > I just took a close look at the COMP_CRC64 macro in xlog.c.
> > This isn't a 64-bit CRC. It's two independent 32-bit CRCs, one done
> > on just the odd-numbered bytes and one on just the even-numbered bytes
> > of the datastream. That's hardly any stronger than a single 32-bit CRC;
> > it's certainly not what I thought we had agreed to implement.
> > We can't change this algorithm without forcing an initdb, which would be
> > a rather unpleasant thing to do at this late stage of the release cycle.
> > But I'm not happy with it. Comments?
> This might be a good time to update:
> The CRC-64 code used in the SWISS-PROT genetic database is (now) at:
> From the README:
> The code in this package has been derived from the BTLib package
> obtained from Christian Iseli <chris(at)ludwig-alpha(dot)unil(dot)ch>.
> From his mail:
> The reference is: W. H. Press, S. A. Teukolsky, W. T. Vetterling, and
> B. P. Flannery, "Numerical recipes in C", 2nd ed., Cambridge University
> Press. Pages 896ff.
> The generator polynomial is x64 + x4 + x3 + x1 + 1.
> I would suggest that if you don't change the algorithm, at least change
> the name in the sources. Were you to #ifdef in a real crc-64, and make
> a compile-time option to select the old one, you could allow users who
> wish to avoid the initdb a way to continue with the existing pair of
> Nathan Myers
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026
In response to
pgsql-hackers by date
|Next:||From: Bruce Momjian||Date: 2001-03-01 02:17:19|
|Subject: Re: Uh, this is *not* a 64-bit CRC ...|
|Previous:||From: Hiroshi Inoue||Date: 2001-03-01 02:05:02|
|Subject: Re: [ODBC] Re: Release in 2 weeks ...|