Delta-update Firefox Aurora package from PPA

Question

I am using Firefox Aurora in my Ubuntu 12.04 which I have installed via its ppa (ppa:ubuntu-mozilla-daily/firefox-aurora). As expected of Aurora, I get an update usually after 2-3 days. I have Firefox Aurora installed in Windows too. There also I get updates in 2-3 days but size of update is usually 4-5 MB, while in Ubuntu it's always around 20 MB.
What is the reason for this difference? Is there any way by which I can download and install only the changes and not the entire Aurora again and again?

Answer 1

Ubuntu does not currently support updating a package using deltas. The dpkg format Ubuntu usage does support delta packages, but the higher-level tools like APT apparently still don't.

• According to When will Ubuntu include delta updates?, this feature has been under discussion since 2009, but not actually finished. The relevant blueprints are:
  • https://blueprints.launchpad.net/ubuntu/+spec/foundations-o-debdelta/ / https://wiki.ubuntu.com/UbuntuDebdeltaSupport
  • Related: https://blueprints.launchpad.net/ubuntu/+spec/foundations-m-rsync-based-deb-downloads
• The corresponding feature in Fedora is called Presto.