[pacman-dev] Incremental package index support?

[Anatol Pomozov]

Hi

On Sun, Mar 24, 2013 at 10:57 AM, Anatol Pomozov
<anatol.pomozov at gmail.com> wrote:
> Hi,
>
> I am an update junkie. I do "pacman -Suy" several times a day. One
> thing I do not like with current pacman is that it redownloads whole
> index file each time I update system.
>
> :: Synchronizing package databases...
>  core                     104.4 KiB   104K/s 00:01 [######################] 100%
>  extra                   1416.9 KiB   171K/s 00:08 [######################] 100%
>  community               1916.6 KiB   204K/s 00:09 [######################] 100%
>
> It is 3.5M it total even if only just a few new packages were added.
> Multiply 3.5M to number of users and you'll get a huge number. IMHO it
> is waste of bandwidth and user time. From other side index is
> incremental by it nature. Could pacman use index format that fits
> incremental updates better?
>
> A naive proposal is to use compressed format for "full fetch" (e.g.
> for users who did not update more than a week), and uncompressed
> append-only index for incremental. On incremental update client sends
> request to server "give me append file file starting from position XXX
> till the end of file", so only delta from the last update will be
> fetched. Then pacman applies the delta to client index.
>
> What do you think about this idea?

Ok, found pacman.conf option "UseDelta" that seems does what I need.
BTW why it is not enabled by default? Isn't saving bandwidth a good
thing?