Re: New module proposal: tracker

[Philip Van Hoof <spam pvanhoof be>]

On Tue, 2009-08-18 at 21:06 +0200, Lennart Poettering wrote:
> On Tue, 18.08.09 18:43, Martyn Russell (martyn lanedo com) wrote:
> 
> >>>> So you are telling me file system notification does not matter much
> >>>> for Tracker's usefulness? That's news to me indeed. But of course
> >>>> leads to the question: what is it then what it offers that desn't need
> >>>> file system notification? Please explain.
> >>>
> >>> Well, for a start, we don't index . prefixed directories, so for
> >>> applications that want to store their bookmarks, contacts, etc they can
> >>> use tracker for that. The Nepomuk ontology describes all of that and how
> >>> the data relates. Those updates do not come from file system updates,
> >>> they come from applications sending us data.
> >>
> >> I guess a problem here is that nobody except the Tracker people
> >> themselves even know what an ontology or Nepomuk actually is. Just
> >> throwing around buzzwords that nobody understands doesn't really help
> >> dumb people like me actually get a grip on what tracker actually is,
> >> and help them understand that it isn't what they thought it was.
> >
> > You could say the same about pulseaudio  ;)
> 
> Not sure this really compares that well... 
> 
> I didn't really play buzzword bingo that much, I guess. I often use
> words like 'glitch-free' and stuff, but at least I wrote a couple of
> blog articles about it, explaing what is supposed to be. Still waiting
> for a really good explanation on planet gnome what ontology or nepomuk
> was.

Sorry to disappoint you in this reply of mine, but here you are either
being intellectual dishonest or you are saying something that you don't
know a lot about because you decided to ignore the posts that you just
claimed don't exist.

We have been writing quite a lot on the subject. Ivan has been writing
on the subject, Martyn has written a blog post about it, Jürg recently
did, ...

I also wrote two tutorials (and these got blogged to pgo too):

http://live.gnome.org/Tracker/Documentation/AppDevelopersManual/IntroductionToRDFandSPARQL
http://live.gnome.org/Tracker/Documentation/AppDevelopersManual/AdvancedRDFandSPARQL

Let's at least keep the discussion fair and professional here. 

> It doesn't matter that you explain to everyone and his dog what
> tracker is about, but it would be good if at least the desktop-devel
> folks would understand what it was about. And as I read the comments
> here I am not the only one who doesn't.

Two parts: tracker-store and tracker-miner-fs

It appears that you know what tracker-miner-fs is about. Let me know if
this isn't accurate then I will repeat a description one more time.

I am going to repeat this one:

The tracker-store is a desktop service that offers the application
developer a query capability against data that it stores. The data that
it stores must be strictly defined by a schema (which is what in RDF is
called an ontology). The schemas that we ship by default are the Nepomuk
ones. The query language is SPARQL. The service provides the opportunity
to the application developer to store. The application developer uses an
extension to SPARQL, SPARQL Update, which we support too. The
communication between application and tracker-store happens over DBus.

Nepomuk's ontologies:
http://www.semanticdesktop.org/ontologies/

SPARQL:
http://www.w3.org/TR/rdf-sparql-query/

SPARQL Update:
http://jena.hpl.hp.com/~afs/SPARQL-Update.html

RDF:
http://www.w3.org/RDF/

Let me know if that was a helpful description for you. I tried hard not
to sound like an old German philosopher ;-).

> (but then again, this is of course a matter of perspective. Maybe I
> never did a better job explaining what PA is about then you did with
> explaining what Tracker is -- but then again I never tried to make PA
> a module of GNOME...)

This is not about PulseAudio. Let's stop that thread before it goes
ridiculously off topic.

-- 
Philip Van Hoof, freelance software developer
home: me at pvanhoof dot be 
gnome: pvanhoof at gnome dot org 
http://pvanhoof.be/blog
http://codeminded.be