[pacman-dev] pacman -Qs first-run performance

[Philipp Überbacher]

Excerpts from Dan McGee's message of 2011-09-01 20:17:47 +0200:
> On Thu, Sep 1, 2011 at 1:14 PM, Denis A. Altoé Falqueto
> <denisfalqueto at gmail.com> wrote:
> > On Thu, Sep 1, 2011 at 2:57 PM, Philipp Überbacher <hollunder at lavabit.com> wrote:
> >> It's really kind of weird that the web search takes longer than the
> >> local search, intuition dictates it should be the other way around.
> >
> > It is not a web search, though. -Ss searches in /var/lib/pacman/sync
> > and -Qs searches in /var/lib/pacman/local.
> Yes, this is definitely not a web search, I'm not sure where that idea
> came from? Is our documentation unclear?

It simply arose because it searches for packages that aren't necessarily
installed. If it only searches everything it knows from the last 'y'
that's fine too.

> > Both are limited by the
> > same I/O bus. Theoretically, you'll have less packages installed than
> > not installed, so the size of /var/lib/pacman/local should be smaller
> > than /var/lib/pacman/sync. Could you compare the sizes of those two
> > directories?
> This won't really be indicative of anything- the sync databases are
> both single-file and compressed, meaning there is no 4K filesystem
> block rounding per file and text compresses well, among other things.
> More useful numbers would be a lot of the commands I dropped in my
> last email.
> 
> -Dan

I ran ncdu anyway, local has 42MiB, sync 1.2MiB. The more interesting
numbers are: Items: 4606.
I don't know whether Items includes directories. sync accounts for 6
files, so from the file structure I assume I have either about 1500 or
2300 packages installed, but there's probably a better way to find out.

Regards,
Philipp