Yum-presto 0.3.9 - FC6 *and* Rawhide

[Thomas M Steenholdt]

Tony Nelson wrote:
> 
> I think the powers that be would want to be shown exactly how much storage
> and how many files would be required for all the pairs of package updates.
> The number of updates for all pairs for a fast-moving frequently updated
> package, e.g. the kernel and its ilk, might be large.  Well, I only notice
> 5, but I may have missed some.  I don't know how to find out all the
> released updates.
> 
>                     n!      n*(n-1)
>     d = C(n,2) = -------- = -------
>                  2*(n-2)!      2
> 
>     n is number of versions (original + updates)
>     d is number of deltas
>     recurrance:  d(n+1) = d(n)+n
> 
>     1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
>     0   1   3   6  10  15  21  28  36  45  55  66  78  91 105

The way I see it, the function is more like

    d = n - 1

Slightly simpler. For every version of a package, we would need to be 
able to update from any previous version, to the current version. I 
don't think it makes sense to be able to have deltas for updating to a 
non-current version, so i guess my suggestion to "keep all possible 
deltas" is inaccurate in this way. What I meant was "keep all possible 
deltas, allowing a user to update from any previous version to the current".

Michael Wiktowy had a perhaps even better suggestion elsewhere in this 
thread, that would further reduce the number of deltas kept, by dropping 
previous deltas (other that current minus one -> current and original -> 
current) after a period of time.

/Thomas