Why do software updates (such as notable examples iTunes and iOS) now download the entire software every time, rather than just a small patch for the portion updated?

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I miss the days of software patches. The program might be 5 gb, but the update patch might be just a fraction of that, and it would apply itself to the installed files. Nowadays it seems more common (or at least increasingly) that the provider just makes you download the entire program in the latest version. So why is this done? It seems like a massive waste of bandwidth.

In: Technology

4 Answers

Anonymous 0 Comments

There are two issues with patches. Either you need a patch from every old version to the current version and every time you release and update to need to regenerate all these patches. Or you just create a patch from the previous version to the next version. If the user is out of date by several versions, then they need to download several patches and apply them all in order.

Neither is particularly difficult, it’s just one more thing to manage. Bandwidth is fast and cheap now, so it’s just easier to make the user download the whole thing again.

Anonymous 0 Comments

>It seems like a massive waste of bandwidth.

Because bandwidth and size are relatively negligible things these days. If a download is 5 gigs, what does it matter, that’ll only take a few minutes to download on most modern broadband that people have. But if you have to write software that does patches in bits and pieces that will increase the installation times, and greatly increase the complexity of the software itself.

Anonymous 0 Comments

for iOS and Mac apps, the entire app bundle is cryptographically signed, so that it’s easy to verify that the app has not been tampered with. This increases security and protects against malware, but also makes it difficult to release patches

every time Apple releases a new version of XCode – even a small delta change – I have to download the entire 6+ GB file to install it

Anonymous 0 Comments

I don’t really understand too much technical stuff, so this is what I thought when I first read your question.

Rather than just one or two things being updated in the software, many different things are tweaked. I reckon that only updating these portions of the software could cause some errors (such as the software overwriting itself?) and therefore it is easier to just download a whole new software and replace it. I’m really not sure though, this is just me having a guess.