Request for Comments: updating RPMs using binary deltas.

[Lamar Owen]

On Thursday 08 January 2004 11:19 am, Chris Ricker wrote:
> SuSE's description of their patch.rpm system is:

> "As of now we are offering so called Patch RPM packages. A Patch RPM
> updates an already installed RPM. It only contains files which have changed
> - therefore it is (much) smaller than the complete RPM package.
> Prerequisite for installation is an already installed basic RPM. The
> packages included on the SUSE LINUX 9.0-CDs/DVD are considered as basic
> RPMs. If you want to update an already installed package, please download
> the smaller Patch RPM package."

That's almost the same system, but with the twist that they assume which RPM 
you have installed.  The only reason I even mentioned having the pristine RPM 
is making sure that the patch is patching the right files.  Pekka already 
touched on that.  And I was wrong.  Ok.

To me doing the delta part is easy; securing the integrity of the subsequently 
installed delta is the slightly harder part.  Getting it integrated into the 
distribution system and update tools is the hard part.

But if SuSE is doing it, it wouldn't be too hard to find out how well it is 
working in practice.  And, yes, it might be nice to use something at least 
mostly compatible so as to not reinvent the wheel.  Unless SuSE hasn't opened 
the code to do it, that is (since it would be inside YaST, they may not have 
opened the code).  But I haven't followed SuSE's stuff in a 'coon's age, so 
someone who is more up on what they are doing would need to respond to that.
-- 
Lamar Owen
Director of Information Technology
Pisgah Astronomical Research Institute
1 PARI Drive
Rosman, NC  28772
(828)862-5554
www.pari.edu