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Re: [subversion-dev] Subversion design document up

From: Greg Stein <gstein_at_lyra.org>
Date: 2000-06-07 03:59:04 CEST

On Tue, Jun 06, 2000 at 06:27:04PM -0400, Jonathan S. Shapiro wrote:
> > I'm glad to hear you agree with me that strong checksums are necessary.
> > I'd settle for CRC or adler32, but SHA sure would be nice.
> I'm not using checksums. I'm using cryptographic hashes. The difference is
> significant. CRCs and adler32's provide a good means of integrity checking,
> but they collide too frequently to serve as *names*. In the DCMS repository,
> the "repository name" of an object *is* its SHA-1 hash. One effect of this
> is to greatly simplify transaction and replication handling.

Ooh. That is a spiffy idea. If you're computing SHA1 hashes anyhow (for
integrity and robustness), then yah... it does provide a unique value.

(well, as much as any 160-bit random value can be called "unique" :-)

I'm not entirely sure that I would want to depend on that, however. One
chance in a bazillion and you (effectively) have a corrupted DB. There
really ought to be another key-portion in there.


Greg Stein, http://www.lyra.org/
Received on Sat Oct 21 14:36:05 2006

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