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OT: Rsync not effective at minor changed packages

Sorry I don't know in which group I have to post this question, but the result
might be interesting for anyone, who does regularly download.

Since the "x11/kdebase" package changed lately from version
2.0-20000920-0 to 2.0-20000920-2 and the package contains allmost
7MByte, I did a test to see how well does rsync if I just copied the
version ...-0 to ...-2 before resynching. Here the result of rsync:

59144 wrote, 6578893 read, 6882072 total, speedup 1.04

This means rsync did practically download the full file, which
astonishes me. Since the change of the package was probably very
minimal, probably not even in the source (...tar.gz) itself, I expected
a much better result. I know packages are compressed, which certainly
makes it worse but still not _that_ worse. I can't belief the the actual
binaries where that much different between those two versions.

I repeated the test again with the "sawfish" package, version 0.31-1 to
0.31-2. While I lost the exact figures, the speedup was about the same.

Why do we have to waste so much bandwide? Isn't there a better way to
accomplish such a minor upgrade of a package than to download the full
package again? Should we start building packages without compression? Or
could we change the compression process to get better results? Or do we
have to limit the count of upgrades per package to once a week?

O. Wyss

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