Fedora Considers Dropping Delta RPMs

[StarterX4]

Delta updates would be great on Arch, where are frequent updates.
Not just because of users with poor internet, but also because of SSD/NVMe storages.
Why reinstall the whole package, and not just apply a "diff"?
Sometimes it's annoying when a huge package is recompiled or even repackaged (because of signing? or some another shit), bringing no real differences, but just wasting time for end users.

[Tian]

Delta updates would be great on Arch, where are frequent updates.
Not just because of users with poor internet, but also because of SSD/NVMe storages.
Why reinstall the whole package, and not just apply a "diff"?
Sometimes it's annoying when a huge package is recompiled or even repackaged (because of signing? or some another shit), bringing no real differences, but just wasting time for end users.

There were repos offering delta updates in 2019, dont know if they still work thoug

https://bbs.archlinux.org/viewtopic.php?id=243247

[uxmkt]

In HPC we learned a decade ago that computation is cheap[...]

In economics you learn that time is money, and if the time to reconstruct an RPM from a DRPM is larger than the time it takes to just download a full RPM from the network, you lose money eventually. Ironically, HPC knows that, because they're replacing their machines every 3-5 years or so for efficiency reasons. Even more ironically, HPC has the fastest networks on the planet, both local and remote (compared to home users), while the CPU clocks run saturated at medium speeds (again, totally unlike your average Linux distro user).

[pegasus]

In economics you learn that time is money,

Economists are the worst at understanding real world. If you want to live a happy life, ignore anything and everything they say.
Sounds like the source of the problem is drpm->rpm step, which I think is not needed at all. So lets get rid of that to improve user experience and do something good for the planet as a consequence.

[Weasel]

In economics you learn that time is money

Only if you're important enough.

[piotrj3]

That's not hard at all, you literally just look at all diffs and count the size you'd have to download. If it's larger than direct entire redownload, go for direct redownload of latest version. Steam also does it.

That is not the hard part. The hard part is that most binary files differ in offsets etc. So there are certain diffrences that will be always present in certain updates often miniscule.

From perspective of such diffs, it would be better to generate more diffs automatically. So eg. when you have 0.10 version, you have diffs to upgrade to 0.10 from 0.9 and seperate diff to upgrade from 0.8 and seperate from 0.7 (so you don't donwnload multiple diffs, just 1) but of course you don't want to generate milions of diffs for every single version so there is part that needs to be benchmarked how many diffs you want.

[George99]

A Problem which occurs frequently with Delta RPMs:

Failed Delta RPMs increased 131.9 MB of updates to 178.5 MB (26.1% wasted)

This is caused by:

/var/cache/dnf/updates-fd4d3d0d1c34d49a/packages/kernel-devel-6.1.13-200.fc37_6.1.14-200.fc37.x86_64.drpm: md5 mismatch of result
/var/cache/dnf/updates-fd4d3d0d1c34d49a/packages/kernel-modules-6.1.13-200.fc37_6.1.14-200.fc37.x86_64.drpm: md5 mismatch of result
Some packages were not downloaded. Retrying.

So I think these delta updates do more harm than good.